Policing the streets

I'm in the market for a car these days. I've been doing the CraigsList search, which is full of scams and people who "can't read or write."
Then, there's the overly paranoid guys.
I got this faaaantastic email back from someone today about a Honda Accord:

"yes. i only take cash and deal with people locally. if you email with "i can pay by bank check" I am reporting you to craigslist and my uncle who works in the FBI"