The money quote:
Friend and fellow blogger Mark of a Free Man ran a post once upon a time about a police force acquiring tactical armored vehicles for their SWAT teams (I would spend the time to dig for a link, but it’s early and I’ve been up all night). His contention was that there was no need for a local police department to have such equipment, a sentiment I happen to share and for the very same reasons. In my opinion police departments need to base their training more on the teachings of Robert Peel and less on the teachings of Robert Rogers.
But you should go read the whole essay at the link above.