In state parks, but I haven't seen it really enforced in most of the US. The point is that litter isn't the primary problem with plastic. Most of the issues with it have nothing to do with the littering of random citizens, to the point that it's not even worth bringing up in a conversation about plastic.

But do you think a citizen who doesn't care about throwing their bottles across the road, will care to vote for a recycling initiative? Education has to start somewhere.