Most likely you are accessing this website because you had some issue with the traffic coming from this IP. This router is part of the Tor Anonymity Network, which is dedicated to providing people with anonymity who need it most: average computer users. This router IP should be generating no other traffic, unless it has been compromised.
While Tor is not designed for malicious computer users, it is inevitable that some may use the network for malicious ends. In the mind of this operator, the social need for easily accessible censorship-resistant anonymous communication trumps the risk. Tor sees use by many important segments of the population, including whistle blowers, journalists, Chinese dissidents skirting the Great Firewall and oppressive censorship, abuse victims, stalker targets, the US military, and law enforcement, just to name a few.
In terms of applicable law, the best way to understand Tor is to consider it a network of routers operating as common carriers, much like the Internet backbone. However, unlike the Internet backbone routers, Tor routers explicitly do not contain identifiable routing information about the source of a packet.
As such, there is little the operator of this router can do to help you track the connection further. This router maintains no logs of any of the Tor traffic, so there is little that can be done to trace either legitimate or illegitimate traffic (or to filter one from the other). Attempts to seize this router will accomplish nothing.
Furthermore, this machine also serves as a carrier of email, which means that its contents are further protected under the ECPA. 18 USC 2707 explicitly allows for civil remedies ($1000/account plus legal fees) in the event of a seizure executed without good faith or probable cause (it should be clear at this point that traffic with an originating IP address of FIXME_DNS_NAME should not constitute probable cause to seize the machine). Similar considerations exist for 1st amendment content on this machine.
If you are a representative of a company who feels that this router is being used to violate the DMCA, please be aware that this machine does not host or contain any illegal content. Also be aware that network infrastructure maintainers are not liable for the type of content that passes over their equipment, in accordance with DMCA "safe harbor" provisions. In other words, you will have just as much luck sending a takedown notice to the Internet backbone providers. Please consult EFF's prepared response for more information on this matter.
For more information, please consult the following documentation:
That being said, if you still have a complaint about the router, you may email the maintainer. If complaints are related to a particular service that is being abused, I will consider removing that service from my exit policy, which would prevent my router from allowing that traffic to exit through it. I can only do this on an IP+destination port basis, however. Common P2P ports are already blocked.
You also have the option of blocking this IP address and others on the Tor network if you so desire. The Tor project provides a python script to extract all IP addresses of Tor exit nodes, and an official DNSRBL is also available to determine if a given IP address is actually a Tor exit server. Please be considerate when using these options. It would be unfortunate to deny all Tor users access to your site indefinitely simply because of a few bad apples.