Police Cars with Built in Microphones

I'm not sure if this has been posted anywhere, but it was brought to my attention recently that police cars have microphones that can pick up conversations that take place on the street. Im not talking about the camcorder, this is a microphone on the outside of the police vehicle.

The following was from the Chicago Times March 25, 2005: ""You could pull into a street corner and, if there's a drug deal going on a half-block away, you can hear what's going on. You could have all the windows shut and the air-conditioning on and you could hear everything going on outside the vehicle," Picardi said.""

prisonplanet.com... (link)

This was new to me, I did not know that this was taking place, but seems to me would be a violation of the 4th amendment. Our police department just started doing this, was wondering if any others are out there doing the same thing. It's getting so you can't do anything without someone watching or listening. Cameras everywhere and now recording devices. To me this is pretty scary. I'm not breaking any laws, but at the same time I don't think that the police force should be aloud to break the laws either. Kinda like when they flip on the sirens and lights just to go through a red light or they speed on the highway when no lights or sirens are going. Are they above the law?

What about ones privacy? Are we losing all our rights? It seems every day something is being taken away or the government is deciding to change the amendments to suit themselves, and we tax payers get to pay for it all, just doesn't seem fair. Our rights are being slowly taken away, but taken away non the less.