Click to see it in all its glory.
I stumbled across this collection of humourously defaced billboards and thought it was good enough to share.
The funny thing about outdoor media (like billboards) is that despite it being intended as a monologue, advertisers end up opening themselves up to some very public feedback, as we can see above.
Plus, advertisers also risk attacks from other outdoor media, as is the case in this example:
For more examples of the audience pushing back on advertisers in outdoor media, have a look at The Sharpie Image.