Yes, there are (U.S.) public agencies that are currently (2017-03-07) streaming real-time video data. I'm not aware of a list of them (would LOVE it, if one such exists), but here's one:
Live Video Stream - NOAA Ship Okeanos Explorer
I'm not familiar with DataTurbine, nor aware of similar tools, but that's not to say they don't exist.
Seattle has been ...
No registry that I am aware of, but some government sites do post all of the webcams within their agency/department/etc., like NPS Air Quality Web Cameras.
I keep a lists of some webcams, here are the ones that have animals.
EarthCam Live Webcam Network has over 500 Search Results for "Animals and Zoos" as well as an Animal Cams section.
Eagle Cam @ ...
Based on my comment, you can use live webcam feeds instead of official CCTV. Or even live youtube streams.
Consider using insecam.org as your source. License unknown.
The world biggest directory of online surveillance security cameras. Select a country to watch live street, traffic, parking, office, road, beach, earth online webcams. Now you can search ...