If I remember correctly, there was a lawsuit regarding the Klan sign. The Klan signed up, the unit of government said, "No, you can't," the Klan said "Yes, we can," the unit of government said, "No, you can't," the Klan said "Yes, we can," it went to court, and it turned out that since there were no rules about who could or could not adopt a highway, the Klan was, alas, right. Darn ol' free speech... (I'll bet there are rules now!)
As for no. 17, I'm trying really hard to just not think about it.