@edgarblythe,
I know there are murmurs and serious articles about the necessity for people not to film/shoot various urban areas, with or without police in the photo. As a long time photography enthusiast (I wasn't bad at it but my vision got fuzzier in time, this before all the automated new stuff. I tended to photo urban areas or sometimes architecture, still keen interests). I still treasure my photos to the max, even the later fuzzier ones. Anyway, there is some fear out there re people photoing, re the nosing around, spying possibilities, possible setups.
When I visited in Chicago with other a2k folk in 2oo6, I was lead to believe via some article that I couldn't photo inside the Bean, and maybe that included the outside. I did it anyway, brat that I am. JoefromChicago told me something like 'not to worry, that doesn't hold water'. I think I remember the forbidding was done by the artist, Anish Kapoor, but don't trust me, except that I had felt warned. I was there early morning, plenty of good photos, alone in the space, including the whole area.
Re filming police and arrests? I suppose the arguments on this will escalate, as even a video can hold some bias, but I think right-to-photo in these situations will win.