I know of some commercial buildings where thefts of their air conditioning units took place on a Sunday night. They were after the copper and aluminum  for scrape value. It cost the building owner $24000.00 to replace the equipment. So the owner put in lighting that has motion sensors and fake cams to try and protect the equipment. Here is a town that has become more proactive about this recurring problem...
"It may be a gimmick or the ultimate answer, but a California city this week okay-ed a draft ordinance that would let businesses install 7,000-volt electric fences to protect sites from rampant copper thieves. As reported by the Sacramento CBS station, the reaction from one business owner to the ordinance says it all: 'It'll be a little fun to watch one of these guys get electrocuted holding my fence trying to rob me.'"