A few thoughts for the indy media camera blockers...
1) You are ensuring that local media personnel get pissed off at protesters, thereby making anything even remotely resembling balanced reporting less and less likely. The people who get sent out to cover things have to come back with something to make a "package" (a story) from. That's how they make their living. When you fuck with them, you push them away. These are the same people who write the voice-overs and edit the stories; they will harbor a grudge and their reporting will continue to become more antagonistic of progressive actions.
2) If they air footage of people blocking their cameras it will appear to their audience as if there is something to hide. There's a story right there for a reporter who got their shots blocked. I can hear the promo now... "What are the protesters hiding? Find out tonight on KATU!!"
3) Local media pool their resources and make them available to other organizations who are free to editorialize as they wish. Without footage of events, stories about protests (negative or positive) don't hit the air and mainstream Amerikkka never knows that they occur.
4) You really should do some more research into how modern tv media works and maybe even do a stint "on the inside" to really figure the shit out and develop effective techniques.
5) Have you heard of free speech or maybe freedom of the press? I have to agree with Chomsky, in the sense that you're either for or against it. Good job employing fascist tactics in an attempt to supress a viewpoint that you just don't happen to like. Perhaps this is the work of some provocateurs?
By the way, I don't work for any corporate media organizations. I have done my homework in order to develop effective propaganda strategies, including a stint working in the news. I am not trying to piss you off; I am trying to point out a dangerous hole in your strategy that could do more PR harm than good.
Good luck and cover your ass.