If we're going to talk abstractions for a second, there is a difference in that we generally limit the government to those actions that we permit them, not to what they can get away with. We permit police certain exceptions not available to the normal citizen, such as (generally) protection from false arrest lawsuits and permission to deadly force in some circumstances. We permit the government to levy taxes but not unequivocably (and if you live in Tennessee, you protest if the government tries to give itself too much power).
I think the Tampa cameras are a police "oh gee isn't technology wonderful" power grab. Now that may not mean they can't get away with it, but I would hope there would be more public pressure against it.
Speaking of the Tampa cameras, have they even worked? The only time I've heard of someone even being questioned was the mis-identification of the construction worker, and that wasn't even the Faceit process. *If* the process is as they are claiming (identiification of criminals), they should at least trot out a few successful arrests. If they can't point to any, then arguably either the software doesn't work (and they should stop wasting their time), or they aren't using the cameras as they are supposed to be used (going back to the "get to play with computers and technology" argument as being the primary purpose of the system, not arresting criminals.)