It’s a sign behind a sign. Somebody is telling someone something.
I wondered if it was written by a long distance hitchhiker hitting a patch of bad weather, but that is probably not likely. I don’t think hitchhikers carry spray paint.
Who is this message for? It is strategically located at a stop light where people will pause and have time to read it (if they are not checking their cell phones). So maybe it’s for us, the traveling public.
Who is it from and why are they telling this? Have they dried out?
Apparently other people. have asked the same questions. A quick Google search finds that this has found it’s way onto the Urban Dictionary.