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.
"You wanna bet?"
Uhm, no thanks. You're going to have to do better than that.
How does your argument demonstrate that checkpoints are not fishing expeditions? The majority of people passing through them are law abiding citizens who must prove that they are law abiding before they are allowed to pass.
From Miriam-Webster's Dictionary: "Fishing Expedition" -- an investigation that does not stick to a stated objective but hopes to uncover incriminating or newsworthy evidence