Not sure if I can post his name, but, you've heard the news. Supposedly he tap some other dude's shoe as a signal for homosexual acts. I'll give you a brief insight of the history of the bathroom gathering. Back in the 1970's, homosexuals was viewed as taboo, and its not as open as it is today. That is, if you are gay, you keep it to yourself and don't come out the closet and publicly announce it to the world as we do today. So, men would secretly go into public places such as the bathroom to fulfill their homosexual fantasies, without anyone knowing, and it still goes on today.
So, to answer your question, I'm sure that glory holes exist. They may have them at homosexual gatherings such as concerts or parties. Glory holes are not exclusive to the homosexual community, but may include other public places as well. Here are some interesting websites I've came across, and it may give you a better understanding of the glory hole community. Also, there are plenty of threads about glory holes on other sites to which I am not permitted to post here.