Huh. Apparently the one down by the Irish Famine Memorial/mega-Walgreens is supposed to close down at 6 pm. I was playing it on Sunday afternoon, though, and spoke with one of the guys from Walgreens who said that sometimes he's working a very late shift (I think it's a 24-hour store) and hears people playing it late at night.

I wouldn't try that in Davis Square, but if I were playing it (quietly!) at 10 pm and someone asked me to stop, I'd be kind of startled.