Many folks use Tor to protect their privacy online. But just like other technologies, this is a double-edged sword. If you are worried about Tor exit nodes being used to find vulnerabilities on your website, you could rely on Tor Blocker to better deal with users coming from Tor exit nodes.
This simple plugin gives you control over visits, comments, registration, subscription, and more. You can also ban any action by its name or key. You have the option to allow Tor users to read your content, register, and even access the admin panel if you choose so. The plugin is free to try but you can always get a premium key to get a more responsive experience.[via]