Police are PUBLIC SERVANTS. They need to maintain that mentality, instead of the power hungry one they possess today. The police force is nothing more than a government enforced gang. The Boys in Blue. They get away with murder and assault everyday by creating stories and blatantly lying. But who do the courts believe? The slimy snakes in the uniforms.
Standing too close to a police scene may interfere with their duties, especially if a suspect with whom they are physically struggling becomes more agitated upon discovering the cop-watcher. Editing, especially of the audio where names have been uttered, should be required by law to protect the identity of the suspect.
If police are not doing anything wrong then they have not reason to worry about who is filming them and why. However this is a two way street it is fine for the public to film Cops just know that Cops are also filming the public in almost all interactions now.
Why should we even have a discussion like this. People should have the right to film police if they wanted to. What would be the argument against such a thing? Police are in the public eye for us in the public. This may be able to keep police held to a standard.