Checkpoints are not a proactive law enforcement technique. They are fishing expeditions that treat everyone as a criminal until each person in line proves themself to not be a criminal.
How far do you want to go? CCTV? Satellite surveillance? Full body scanning on pedestrians at random? After all, one person in this thread implied that when you're in public you don't have Constitutional protections anymore.
You wanna bet? You park 4 cruisers out on a busy street in high crime areas and you will be amazed at what you find behind the wheel and under the front seat. Until people started complaining about racial profiling I knew of towns that would stop anyone that looked like they didn't live in an area so as to cut down on the crime rate.
If you were 17, dressed like a gang banger and driving into areas that it was obvious that you didn't live you got pulled.