Avoid being implicated in criminal activity when using Tor

Question

What steps does a Tor user need to take to ensure that he or she doesn't become implicated in other Tor users' criminal activity?

For example, I recently came across a Tech Republic article by Patrick Lambert saying that acting as a relay is dangerous:

You may want to act as a relay yourself. This will allow other people to use your computer to relay traffic. In order to do that, simply go to the Control Panel option inside of Vidalia and set up relaying. The thing to remember here is that by doing that, you are helping out the TOR community. However, you have no way to know what kind of traffic will transit over your system. Some of it may be illegal, and it may expose you to law enforcement actions.

I find this peculiar; I only thought people running exit nodes were putting themselves in harm's way, not relay nodes.

Answer 1

I think the author is referring to people running exit nodes, not those who run middle or entry nodes. By design, the Tor protocol doesn't allow the entry or middle nodes to decipher what is being received or sent (assuming the keys for the nodes are not compromised by some other fashion), only the inbound and outbound nodes are known. Therefore, it should be safe to say that running an entry node or middle node is okay (in most cases) as you do not know what is going through.

Essentially, you can cooperate with your local law enforcement by saying that you have little evidence of wrongdoing to give. You can even give them your node logs and private keys for the node if they request for it (not that you should without a court warrant), and if your log settings are default they would at most be able to determine which nodes you've been talking to, not the contents of your traffic.

However, there are certain countries that frown upon citizens making their own Tor nodes, as they believe that the Tor network is mainly used for criminal activity. Even if you run a Tor middle node, they might put you in greater surveillance as you are deemed "suspicious" by them. Most consumer level ISPs also do not like their customers running servers (which by definition a Tor node is) unless you upgrade to their business plans.

My advice: do so, but understand more about your country's laws and your ISPs restrictions to avoid getting into trouble.