Actually, they aren't the same as litter. They are non-conforming signs. It's a sign/building code violation. The act of putting a sign on a r.o.w. is not illegal. HAving it out there , otoh, might be. If it's placed on private property and there isnt a permit, the land owner can be held responsi...
Yeah Sherpa Guides.... I don't know if they're just really outdated or if they just make stuff up.