Regarding installing cameras, are you sure you need power?
I had a friend who used to work security at a large retailer. Sometimes he suspected an employee was stealing but he had no evidence. So he would call the employee into his office and they would sit down at a table and on the table was a stack of VCR tapes (this was a while ago). The tapes were either empty or might be from cameras in a different part of the store. My friend would look the employee in the eye, tap the stack of tapes and say, "This will go a whole lot better if you tell me what you have been doing than if I have to tell you what you have been doing." Oftentimes the employee would confess. If they didn't confess they stopped coming to work. Either way, no more theft.
So . . . what about getting a non-working (or very cheap, working) security camera and have it installed so that it points to the trash area? Install a dummy outlet as well, or some type of junction box so that it at least appears the camera has power.
Then send out a notice that cameras have been installed near the trash area (which is true - the notice just won't say that they have no power).
Working cameras provide incentive for residents to put the trash where it belongs, and then provide evidence if they do not comply. But the primary goal is the incentive (and putting an end to the scathing emails). A non-working camera may help you get that.