Super-soakers loaded with filtered (to remove the lumps) paint. That and flame throwers are my two favorites so far.
Too many cameras that can be checked on your way in. Gas stations, banks, etc, etc, etc. I would prefer a distance of at least 100 yards or more to provide more isolation to the event itself. I would hate to get caught ruining a camera that undoubtedly will run in the tens of thousands. Besides paintballs and supersoakers.... all they would have to do is just wipe off the window and they are back in business.
Theres also the survalence cameras that they are starting to put up in some of the high crime areas and such, takeing the lead from the Brits.
Yup, as our basic rights to privacy gets erroded away. One day as a safety concern we will be required to turn our guns in.