Glossary · Network
Tor exit node
The last relay in the Tor network, whose IP address is what a destination site sees.
Traffic through Tor leaves the network at an exit node, so the destination sees the exit node's address and nothing about the origin. The list of exit nodes is published by the Tor project itself, which makes detection exact rather than probabilistic.
Tor traffic is not evidence of wrongdoing. Journalists, researchers, and people in censored networks rely on it. It does mean you have no geographic or network information about the user.
For high-value actions, the sensible treatment is additional verification rather than a block, unless your risk model specifically justifies one.