It is well settled law that looking at a car's license plate and checking that against a list of license plates from cars reported stolen is fully constitutional. The ACLU has no problem with that kind of search.
Now, fast forward. Suppose you have a camera that looks at every license plate that wanders into its field of vision on a squad car. And, suppose that this camera is attached to a computer that can read the license plate. And, suppose that the computer automatically checks every license plate it sees against the list of cars reported stolen. Several companies now offer this technology and it works very well. The police using this technology catches ten times as many stolen cars as the pre-computer cops did, and the systems cost just $20,000 each (about 10% of what they cost two years ago).
Slightly, but only slightly more controversial, is the idea of mounting cameras a lamp posts and having them constantly search for stolen cars.
Car theft was already hard. The vast majority of stolen vehicles are eventually recovered (a far greater percentage than any other kind of theft) although often worse for wear. This makes it even more difficult.
And, it isn't the only car thief catching technology out there. Gun control opponents have always talked about the deterrent effect of the having a significant number of homeowners own guns, forcing burglars to play a lottery with their lives in those neighborhoods. It isn't well established, but it is certainly discussed. Now, car thieves face a similar, although more subtle lottery. It won't kill them, but it could send them to prison. It is the "lojack lottery." Often, it isn't even a true lojack, but a car navigation system. This isn't a big deal to the teenager who joyrides a few miles and dumps a car. But, it is a very big deal to a chop shop that steals dozens of cars a week or more and rips them to pieces for parts, or a car thief who steals cars intact and tries to alter the VIN numbers on them. A single lojack equipped car could expose and shut down an entire shop and result in the arrest of everyone there.
Bottom line: One of the most profitable kind of organized theft may be seeing its waning days due to technology.