There was one of those comic book/superhero/sci-fi conventions downtown over the weekend. They are for-profit enterprises and take place all over the country, or at least anywhere there is enough population to buy sufficient tickets.
There was someone wearing a Star Trek uniform shirt at the Blues Museum opening. As I walked back to my office afterward I found this group on Washington Avenue. Wish I had more time to hang out around the convention center. There was probably a lot of this on the street. Sadly, though, duty called.
In general, I do not recommend crossing Washington Avenue, a busy street, with your face in a smart phone.