It should probably be pointed out that the problem here is NOT that the police have automatic weapons, armored vehicles and other light infantry war fighting gear. I have 2 of those three sorts of things myself (Light infantry kit and armored vehicles), but I don't find myself struck by the need to drive around violating people's constitutional rights, arresting them without justification because I feel like it and generally assaulting people because I am more powerful than them.
The problem is that police in some instances, have failed to understand and properly follow established law and constitutional restrictions on their activities under the law. The arrest and light abuse of the two reporters is a perfect example. The armored vehicles and battle rifles didn't enter into the equation at all. It was the lack of lawfully supported Probable Cause and apparent disregard for basic precepts as the 1st amendment that led the officers to arrest the reporters, thinking that it would be a reasonable action.
Take away the armored vehicles and M-16s but do nothing to sort out the abuse and violations of rights under color of law, and you'll still have the same problems, just with less of a military look to them. They'll still be violations of rights, and they'll still be wrong under both the law and the constitution.