Unknown to most people, it's been unlawful to swear on public land in Michigan for years. Generally, this law is pretty much ignored by everyone but once in awhile you'll hear about it being used to rid say a state or city owned park or beach of 'undesirables'.
The most notable recent case that I can recall was when a guy was arrested for screaming obscenities at his neighbor while sitting in a canoe moored to his dock on a small river, actually more of a wide stream, which was the boundary between their two pieces of property. But since the stream was legally ruled as being navigable (meaning you could float a 12 inch diameter log down it) and because it eventually emptied into a lake where there was a public access site (where boats could be launched) this made the surface of the river, and the lake for that matter, public 'property' and thus the law applied. Now if the guy had stood on the shore or even ON his dock, he could have sworn all he wanted to since he would technically have still been on his own property.
Of course, Michigan also had another almost universally ignored law and that was that you could NOT drink alcoholic beverages anywhere, even on your own private property, if someone walking past your property on a public right-of-way, say a sidewalk or street, could actually SEE you consuming the alcohol. Now if you put up a fence that blocked the view of where you were consuming these drinks that was fine. Which was why any bar or restaurant that had an outdoor seating area, like a patio, had to put up a fence that was at least 5 1/2 to 6 feet high so as to be in technical compliance of the law. Again, the only time we ever heard of it being enforced was when someone wanted to cause trouble for a neighbor or when some owner was giving another place of business a hard time.