Man, I hadn't thought of that as being a threat.
There are probably zillions of brands of inexpensive, insecure cameras out there from companies that have gone out of business and which were poorly-set-up or configured. Usually not a huge issue, but for military operations in urban areas, it's gonna be a pain.
Countering that is going to be tough.
Maybe disallow security cameras above the third story or something like that, so that any one camera can only see so much. If you can break into one way up and rotate it, which it sounds like they did, then you have good odds of being able to see a lot.
Or disguise the military hardware, which also helps address humans who might be spying.