Years ago (probably around 1998 through 2010 for sure) whenever I was in a rush line for a Broadway show, there would always be at least one or two people in line with me who were posters on ATC. Sometimes just to make the hours pass, we would try to guess each other's screen name just by talking about theatre. You would be surprised how often total strangers would be able to guess correctly.
Once (probably Mar., 2015) I was seated in the St. James theater for an early preview of Something Rotten!. It was during that period when they were offering tickets for around $14. Anyway I began to chat with the young lady sitting next to me -- she was probably in her 20's. Eventually she told me she was an avid ATC lurker and an occasional poster. After about 10 minutes or so of mutual conversation, she correctly told me my screen name -- she said I spoke just the way I posted. It didn't alarm me because it was all in fun. However, when I tried to guess her screen name, she would not confirm or deny my guesses -- she had a real poker face.
Of course, that incident was over 6 years ago. In recent years when I have been in various Broadway rush lines, people I chat with usually know little or nothing about this message board, let alone are active posters. Just saying.