"In fact, four out of five of the boroughs with the most cameras have a record of solving crime that is below average." I really hate when they don't tell you

"In fact, four out of five of the boroughs with the most cameras have a record of solving crime that is below average." I really hate when they don't tell you the marginal benefit, just the absolute result. I would assume that the places with the most cameras are the ones with the most crime. (The relevant urban legend is that some time in 1917, Ukrainian communist rebels noticed that the provinces with the most sick people also had the most doctors -- so they rose up and killed the doctors)