Wait...Did you just argue that gathering in a park (a public gathering place) and playing a board game can be illegal? Where do you live that has laws like that?
I believe it's relatively common to gamble on dominoes, and gambling is often illegal. Even so, it's an innocuous crime and probably not the real reason they were hassled.
Today I learned that people gamble on dominoes. Not that I agree with gambling, or with it being illegal, but I suppose that is more justified than just playing dominoes.
