I used to use this method, among others, to fingerprint Tor nodes. I used murmurhash3 so it was compatible with shodan, too.
> i'm curious, fingerprint in what way/purpose? all the relays are publicly listed by the Tor Project, so i'm guessing you mean something other than "x computer is a tor node"
I understand the confusion. I was typing fast. I meant Tor hidden services. I ran a service called torwhois that collected data and shared it.