@xianc78 I suspect that has something to do with that you have the right to do lots of crazy stuff in your own home, in contrast to posting things online which is more like walking around shouting in the outside world.

Sure, someone could argue that a sign you put up in your front yard can be seen from outside, but to defend the sign you could say that the sign is on your own land for your own purposes, nobody's business what you do there, and you would have a pretty strong case I think.