It’s Legal to Ignore Those Homemade NO PARKING Signs
Have you ever been in this situation before? You wanna go for a nice walk on the Pasco riverfront. You scope out a nice neighborhood to park in. Then you see it, a "no parking" sign that doesn't look legit. It may be drawn up on paper. It may look like the real thing.
Unless it comes directly from the city government, officials say "ignore it."
Road Rules
City streets are public and are supposed to be used by all. Your DRIVEWAY is zoned, so people can't park there without your permission.
The only fake sign I'd watch out for is the "We carry licensed guns" sign. I wouldn't agitate those folks.