To average citizens, these fake towers could be harmful. For one, it is an invasion of privacy if they are spying on the cell phones within the area. Also it can make the phones much slower which aggravates people and could be bad if you needed the service.
     They are probably located by military bases either because they are being run by the government in order to watch the military and any spies. It could also be a foreign government or spies in order to get information from our government.
     In my opinion, it is probably a foreign government because our government doesn't need fake towers to spy on people.