i'd probably say i go on there too and tell them my username so we can talk or something
Personally I would try to sit near them and stealthily try to see what their username is. If it's someone I had never interacted with, I would ignore them, but if it was someone I knew I ABSOLUTELY would say something, cuz what are the chances?
It hit me just now that I still haven't met anyone from PC. Though this will change in time for sure.