This is apparently not just in responce to the violent clearing of the #OccupyOakland site this morning, but also quite a bit about the man who was filming on 11.2.11 who got shot - for no reason - by a policeman's rubber-clad bullet (video link). From the ACLU Press Release:

"I was filming police activity at Occupy Oakland because police should be accountable," said Campbell. "Now I'm worried about my safety from police violence and about retaliation because I've been outspoken." "Excessive police force is never acceptable, especially when it's in response to political protest," said Linda Lye, staff attorney at the ACLU of Northern California.

Police also fired other projectiles at individuals who posed no risk of harm, but were clearly engaged in First Amendment protected activity, such as filming police at a demonstration. This conduct violates the Fourth Amendment by subjecting protesters who posed no safety concerns to unnecessary and excessive force and violates the First Amendment by interfering with their rights to assemble and demonstrate.

They highlight the flash-bang grenade incidents of 10.25.11 and 11.2.11 but also all manner of outrageous, assaultive, and patently unAmerican acts by the police in the face of peaceful/non-violent demonstrators.At the bottom of the ACLU page are 2 links to the filing and one an order from a judge, both in annoying pdf.