I was fascinated by this once I learned how it worked. At the time I was learning php and wrote a script that would draw graphics based on the requesting ip address and return as gif, then used that as my avatar on a few phpbbs. Learned a lot.

That was a troll feature. It usually showed any user his own information.

MAYBE some forum doxxed users by posting their informatio? but I didn't see any.

Had a friend who made his own nice one, would then visit the thread, and figure out "who is viewing it" and show your username. ;)

Just like the days of DoSing an IP from a COD Lobby