Of course they should. There are many fine members of law enforcement but as in any profession, there are also a few bad characters. These methods can help weed those folks out and protect both the citizen and the officer.
Morph - that was a great idea to have you on speaker when your son was stopped. I think that more parents should do that. If you get caught committing a traffic infraction, then a ticket and fine is in order. A bullet is not.