Perhaps we need a federal law that says you can film cops doing their job so things like this don't happen.

http://www.pslweb.org/liberationnews/news/jeremy-marks-home-raided.html

I still don't understand why they don't want to be filmed. Don't most police cars have dash cams now anyways? Plus if I was a cop I'd want EVERYTHING filmed so I'd have a record of what happened, and in case I got hurt there would be evidence of who did it.