My answer to this is yes and no. I have never heard of illegal activity at the arcades, but I have heard of some applying age limits during certain hours. Some arcades in my area (San Diego) used to kick kids out at cerfew. I know Dave & Busters is an adult arcade, where kids are not admitted unless accompanied by a parent during certain hours. When I was visiting Reno once as a kid, they did not allow kids in the arcade under 14 during school hours.
There are some without age limits, too. At Nickel City where I go now to play, I beleive there is no age limit. I don't think Boomers has an age limit, but I could be wrong.