I think it will depend on how big your operation is. If you have a handful of plants they will probably just destroy them but a significant amount that is worth their while, they may install cameras. I dont know what the magic number is but i would imagine if you had maybe 10+ in an area they might set up a camera. It has to be financially worth there while, setting up a camera for a few plants is kinda a waste of police resources when there could be bigger fish to fry.
If you find a camera what about just smashing the damn thing or remove the digital card or whatever recording media they are using and then never returning.
Or if you have the finances you could set up your own cameras and catch them before they catch you