The magic word is "AMORTIZE" from the root word "mort"---meaning death.
Y'know words like "mortuary" "mortality"mortify" mortician"and "mortgage".
AMORTIZATION legally kills a billboard. So we had a billboard funeral at
SFMOMA while the OAAA was having its reception there. We put some signs
up in the park across the street from SFMOMA. The outdoor advertising
industry is trying to convince us all that billboards serve some public art
function, so I'm sure they were quite pleased that the tools at SFMOMA
threw a party for the OAAA! Okay so these billboards have been up in our
neighborhoods for decades, and our signs were up for not even fifteen minutes
before security told us the signs had to come down. They would call the real
police if we did not take down our signs. Well, we were good citizens, when
authorities tell us to take down signs, we don't sue them. But the billboard
industry can ignore the law? Shame on SFMOMA and shame on the OAAA.

Here's a listing of some of the slogans we put up:

Degas, Picasso, and a forty
Complete corporate control of culture
We're trying to raise children here
Dung is art, billboards are crap
Please don't offer me another drink
Drive beer, smoke cars, drink cigarettes
Get out of our neighborhoods
Less billboards, more public words
200 bucks to get sterilized?
Murals r art, billboards r trash
Street corner pushers
Commercial speech is not free speech