So how do AIs find each other on the net?

[HRogge]

"So how do AIs find each other on the net?" Via any number of dating sites, just like everyone else.

More seriously, there's so much traffic on the Internet that looking for signs of an individual AI would be a fruitless task. The new AI is going to have to look for the AI community - and that probably results in finding the Hacker Underspace.

Or you just send an email to one of the well known AIs in the network. Instead of searching and hoping to contact a member of a group without a membership list, just use known ones as a "bootstrap contact".