Abuse FAQ

Ótimo. É exatamente por isto que nós implementamos as políticas de saída.

Cada relé do Tor tem uma política de saída que especifica qual tipo de conexões de saída são permitidas ou negadas por aquele relé. As políticas de saída são propagadas para os clientes Tor através do diretório, assim clientes irão automaticamente evitar escolher relês de saída que recusariam-se "sair" para a destinação pretendida por eles. Desta maneira, cada relé pode decidir os serviços, hospedagens e redes que querem permitir conexões para, baseado no potencial de abuso e sua própria situação. Leia a postagem do suporte sobre problemas que você pode encontras se você usar a política de saída padrão e então leia as dicas do Mike Perry para executar um nós de saída com o mínimo de preocupação.

A política padrão de saída permite acesso para vários serviços populares (ex.: navegar na web), mas restringe alguns devido o potencial de abuso (ex.: email) e alguns desde que a rede Tor não consiga lidar com o carregamento. Você pode mudar a sua política de saída editando seu arquivo torrc. Se você quer evitar a maioria, senão todo o potencial abuso, configure-o para "rejeitar :". Esta configuração significa que seu relé será usado para retransmissão de tráfego dentro da rede Tor, mas não para conexões para websites externos ou outros serviços.

Se você autoriza qualquer conexão de saída, tenha certeza que a resolução de nomes funciona (isto é, que seu computador pode resolver os endereços de Internet corretamente). Se existirem qualquer recursos que o seu computador não pode alcançar (por exemplo, você está atrás de um firewall restritivo ou filtro de conteúdo), por favor, explicitamente rejeite eles na suas política de saída caso contrário usuários do Tor também serão impactados.

Criminosos já podem fazer coisas ruins. Desde que eles pretendem quebrar as leis, eles já possuem várias outras opções avaliáveis para fornecer melhor privacidade que o Tor proporciona. Eles podem roubar telefones celulares, usá-los e jogá-los em um fosso; eles podem invadir computadores na Korea ou no Brasil e usá-los para lançar atividades abusivas; they can use spyware, viruses, and other techniques to take control of literally millions of Windows machines around the world.

Tor aims to provide protection for ordinary people who want to follow the law. Only criminals have privacy right now, and we need to fix that.

Some advocates of anonymity explain that it's just a tradeoff — accepting the bad uses for the good ones — but there's more to it than that. Criminosos e outras pessoas más pode ter a motivação para aprender como conseguir um bom anonimato e muitos tem motivação financeira alta para alcançar isto. Sendo capazes de roubar e usar identidades de vítimas inocentes (roubo de identidade) torna isto ainda mais fácil. Pessoas normais, por outro lado, não têm tempo ou dinheiro para gastar tentando descobrir como conseguir privacidade online. Este é o pior de todos os mundos possíveis.

Portanto sim, criminosos podem usam o Tor, mas eles já têm melhores opções e parece improvável que tirar Tor do mundo irá impedi-los de fazer suas más ações. Ao mesmo tempo, Tor e outras medidas de privacidade podem combater o roubo de identidade, crimes físicos como perseguição e assim por diante.

Distributed denial of service (DDoS) attacks typically rely on having a group of thousands of computers all sending floods of traffic to a victim. Since the goal is to overpower the bandwidth of the victim, they typically send UDP packets since those don't require handshakes or coordination.

But because Tor only transports correctly formed TCP streams, not all IP packets, you cannot send UDP packets over Tor. (You can't do specialized forms of this attack like SYN flooding either.) So ordinary DDoS attacks are not possible over Tor. Tor also doesn't allow bandwidth amplification attacks against external sites: you need to send in a byte for every byte that the Tor network will send to your destination. So in general, attackers who control enough bandwidth to launch an effective DDoS attack can do it just fine without Tor.

Primeiro de tudo, a política de saída padrão do Tor rejeita todo o tráfego da porta de saída 25 (SMTP). Portanto o envio de spam por email através do Tor por padrão não funcionará. It's possible that some relay operators will enable port 25 on their particular exit node, in which case that computer will allow outgoing mails; but that individual could just set up an open mail relay too, independent of Tor. Resumidamente, Tor não é útil para spam, porque quase todos relays da rede Tor se recusam a entregar o email,.

Claro que não é tudo sobre entregar o email. Spammers podem usar o Tor para: conectar para abrir proxies HTTP (e de lá para servidores SMTP); conectar com scripts CGI mal escritos de envio de e-mail; e para controlar botnets - isto é, para se comunicar secretamente com exércitos de computadores comprometidos que enviam o spam.

Isto é uma pena, mas note que spammers já estão se saindo bem sem o Tor. Também lembre que muitos dos seus meios de comunicação mais sutis como pacotes UDP falsificados) não podem ser usados no Tor, porque ele apenas transporta conexões TCP formadas corretamente.

Not much, in the grand scheme of things. The network has been running since October 2003, and it's only generated a handful of complaints. Of course, like all privacy-oriented networks on the net, it attracts its share of jerks. Tor's exit policies help separate the role of "willing to donate resources to the network" from the role of "willing to deal with exit abuse complaints," so we hope our network is more sustainable than past attempts at anonymity networks.

Since Tor has many good uses as well, we feel that we're doing pretty well at striking a balance currently.

If you run a Tor relay that allows exit connections (such as the default exit policy), it's probably safe to say that you will eventually hear from somebody. Abuse complaints may come in a variety of forms. For example:

  • Somebody connects to Hotmail, and sends a ransom note to a company. The FBI sends you a polite email, you explain that you run a Tor relay, and they say "oh well" and leave you alone. [Port 80]
  • Somebody tries to get you shut down by using Tor to connect to Google groups and post spam to Usenet, and then sends an angry mail to your ISP about how you're destroying the world. [Port 80]
  • Somebody connects to an IRC network and makes a nuisance of himself. Your ISP gets polite mail about how your computer has been compromised; and/or your computer gets DDoSed. [Port 6667]
  • Somebody uses Tor to download a Vin Diesel movie, and your ISP gets a DMCA takedown notice. See EFF's Tor DMCA Response Template, which explains why your ISP can probably ignore the notice without any liability. [Arbitrary ports]

Some hosting providers are friendlier than others when it comes to Tor exits. For a listing see the good and bad ISPs wiki.

For a complete set of template responses to different abuse complaint types, see the collection of templates. You can also proactively reduce the amount of abuse you get by following these tips for running an exit node with minimal harassment and running a reduced exit policy.

You might also find that your Tor relay's IP is blocked from accessing some Internet sites/services. This might happen regardless of your exit policy, because some groups don't seem to know or care that Tor has exit policies. (If you have a spare IP not used for other activities, you might consider running your Tor relay on it.) In general, it's advisable not to use your home internet connection to provide a Tor relay.

Sometimes jerks make use of Tor to troll IRC channels. This abuse results in IP-specific temporary bans ("klines" in IRC lingo), as the network operators try to keep the troll off of their network.

This response underscores a fundamental flaw in IRC's security model: they assume that IP addresses equate to humans, and by banning the IP address they can ban the human. In reality, this is not the case — many such trolls routinely make use of the literally millions of open proxies and compromised computers around the Internet. The IRC networks are fighting a losing battle of trying to block all these nodes, and an entire cottage industry of blacklists and counter-trolls has sprung up based on this flawed security model (not unlike the antivirus industry). The Tor network is just a drop in the bucket here.

On the other hand, from the viewpoint of IRC server operators, security is not an all-or-nothing thing. By responding quickly to trolls or any other social attack, it may be possible to make the attack scenario less attractive to the attacker. And most individual IP addresses do equate to individual humans, on any given IRC network at any given time. The exceptions include NAT gateways which may be allocated access as special cases. While it's a losing battle to try to stop the use of open proxies, it's not generally a losing battle to keep klining a single ill-behaved IRC user until that user gets bored and goes away.

But the real answer is to implement application-level auth systems, to let in well-behaving users and keep out badly-behaving users. This needs to be based on some property of the human (such as a password they know), not some property of the way their packets are transported.

Of course, not all IRC networks are trying to ban Tor nodes. After all, quite a few people use Tor to IRC in privacy in order to carry on legitimate communications without tying them to their real-world identity. Each IRC network needs to decide for itself if blocking a few more of the millions of IPs that bad people can use is worth losing the contributions from the well-behaved Tor users.

If you're being blocked, have a discussion with the network operators and explain the issues to them. They may not be aware of the existence of Tor at all, or they may not be aware that the hostnames they're klining are Tor exit nodes. If you explain the problem, and they conclude that Tor ought to be blocked, you may want to consider moving to a network that is more open to free speech. Maybe inviting them to #tor on irc.oftc.net will help show them that we are not all evil people.

Finally, if you become aware of an IRC network that seems to be blocking Tor, or a single Tor exit node, please put that information on The Tor IRC block tracker so that others can share. At least one IRC network consults that page to unblock exit nodes that have been blocked inadvertently.

Even though Tor isn't useful for spamming, some over-zealous blacklisters seem to think that all open networks like Tor are evil — they attempt to strong-arm network administrators on policy, service, and routing issues, and then extract ransoms from victims.

If your server administrators decide to make use of these blacklists to refuse incoming mail, you should have a conversation with them and explain about Tor and Tor's exit policies.

We're sorry to hear that. There are some situations where it makes sense to block anonymous users for an Internet service. But in many cases, there are easier solutions that can solve your problem while still allowing users to access your website securely.

First, ask yourself if there's a way to do application-level decisions to separate the legitimate users from the jerks. For example, you might have certain areas of the site, or certain privileges like posting, available only to people who are registered. It's easy to build an up-to-date list of Tor IP addresses that allow connections to your service, so you could set up this distinction only for Tor users. This way you can have multi-tiered access and not have to ban every aspect of your service.

For example, the Freenode IRC network had a problem with a coordinated group of abusers joining channels and subtly taking over the conversation; but when they labeled all users coming from Tor nodes as "anonymous users," removing the ability of the abusers to blend in, the abusers moved back to using their open proxies and bot networks.

Second, consider that hundreds of thousands of people use Tor every day simply for good data hygiene — for example, to protect against data-gathering advertising companies while going about their normal activities. Others use Tor because it's their only way to get past restrictive local firewalls. Some Tor users may be legitimately connecting to your service right now to carry on normal activities. You need to decide whether banning the Tor network is worth losing the contributions of these users, as well as potential future legitimate users. (Often people don't have a good measure of how many polite Tor users are connecting to their service — you never notice them until there's an impolite one.)

At this point, you should also ask yourself what you do about other services that aggregate many users behind a few IP addresses. Tor is not so different from AOL in this respect.

Lastly, please remember that Tor relays have individual exit policies. Many Tor relays do not allow exiting connections at all. Many of those that do allow some exit connections might already disallow connections to your service. When you go about banning nodes, you should parse the exit policies and only block the ones that allow these connections; and you should keep in mind that exit policies can change (as well as the overall list of nodes in the network).

If you really want to do this, we provide a Tor exit relay list or a DNS-based list you can query.

(Some system administrators block ranges of IP addresses because of official policy or some abuse pattern, but some have also asked about whitelisting Tor exit relays because they want to permit access to their systems only using Tor. These scripts are usable for whitelisting as well.)

Não há nada que os desenvolvedores do Tor possam fazer para rastrear usuários da rede Tor. As mesmas proteções que impedem as pessoas más de quebrar o anonimato do Tor também nos impedem de descrobrir o que está acontecendo.

Alguns fans sugeriram que nós redesenhassemos Tor para incluir uma backdoor. Existem dois problemas com essa ideia. Primeiro, isto tecnicamente enfraquece muito o sistema. Ter uma maneira central de ligar usuários com suas atividades é um prato cheio para todos os tipos de invasores; e os mecanismos de política necessários para garantir um tratamento correto dessa responsabilidade são enormes e não resolvidos. Second, the bad people aren't going to get caught by this anyway, since they will use other means to ensure their anonymity (identity theft, compromising computers and using them as bounce points, etc).

This ultimately means that it is the responsibility of site owners to protect themselves against compromise and security issues that can come from anywhere. This is just part of signing up for the benefits of the Internet. Você deve estar preparado para proteger-se contra maus elementos, de onde quer que eles venham. Rastreamento e aumento da vigilância não são a resposta para prevenir abusos.

Mas lembre, isso não significa que o Tor é invulnerável. Traditional police techniques can still be very effective against Tor, such as investigating means, motive, and opportunity, interviewing suspects, writing style analysis, technical analysis of the content itself, sting operations, keyboard taps, and other physical investigations. The Tor Project is also happy to work with everyone including law enforcement groups to train them how to use the Tor software to safely conduct investigations or anonymized activities online.

The Tor Project does not host, control, nor have the ability to discover the owner or location of a .onion address. The .onion address is an address from an onion service. O nome que você vê acabando em .onion é um serviço onion descritor. É um nome gerado automaticamente que pode ser localizado em qualquer relé Tor ou cliente em qualquer lugar na Internet. Serviços Onion são projetados para proteger ambos, o usuários e o fornecedor do serviço, de descobrirem quem eles são e de onde eles são. The design of onion services means the owner and location of the .onion site is hidden even from us.

But remember that this doesn't mean that onion services are invulnerable. Traditional police techniques can still be very effective against them, such as interviewing suspects, writing style analysis, technical analysis of the content itself, sting operations, keyboard taps, and other physical investigations.

If you have a complaint about child abuse materials, you may wish to report it to the National Center for Missing and Exploited Children, which serves as a national coordination point for investigation of child pornography: http://www.missingkids.com/. Nós não vemos links que você reporta.

We take abuse seriously. Activists and law enforcement use Tor to investigate abuse and help support survivors. We work with them to help them understand how Tor can help their work. In some cases, technological mistakes are being made and we help to correct them. Because some people in survivors' communities embrace stigma instead of compassion, seeking support from fellow victims requires privacy-preserving technology.

Our refusal to build backdoors and censorship into Tor is not because of a lack of concern. We refuse to weaken Tor because it would harm efforts to combat child abuse and human trafficking in the physical world, while removing safe spaces for victims online. Meanwhile, criminals would still have access to botnets, stolen phones, hacked hosting accounts, the postal system, couriers, corrupt officials, and whatever technology emerges to trade content. They are early adopters of technology. In the face of this, it is dangerous for policymakers to assume that blocking and filtering is sufficient. We are more interested in helping efforts to halt and prevent child abuse than helping politicians score points with constituents by hiding it. The role of corruption is especially troubling; see this United Nations report on The Role of Corruption in Trafficking in Persons.

Finally, it is important to consider the world that children will encounter as adults when enacting policy in their name. Will they thank us if they are unable to voice their opinions safely as adults? What if they are trying to expose a failure of the state to protect other children?