The Automatic Nanny.
A message board questioner asked if anyone had some advice about getting out of a speeding ticket -- or, at least, not letting his insurance company find out that he'd gotten it. Over half of the replies were something like this one. "There's a guaranteed way to avoid speeding tickets: don't speed."
Great, yeah, I'm sure that helps the guy out. Regardless of what you think of the ridiculous speeding laws, (45 zones that turn to 35 just in time to go down a hill, and cops that park below that giving 43-in-a-35 tickets. Yes, I've seen that happen to a friend while I was in the car,) the point is that you shouldn't bother to stick your nose in the questioner's business. He asked a simple question, and if you don't have a constructive answer, just leave it be.
This brings me to: No, really, I mean it!
Signs that tell you not to do things that you're already not allowed to do. Red means stop in Beaverton! Great, because in Portland it means ram the next car you can find. No driving on shoulder! On every convenience store door, Don't buy alcohol / tobacco / bombs for minors! Thanks for the heads up, those 6-year-olds wanted some whiskey. Drug free zone! So, when you're NOT in a drug-free zone (they've got prostitution-free, too,) you can shoot up whatever you like with abandon?
I want to get some ballpoint pens made that read: Caution -- do not stab into eyes. Serious injury may occur.