I found this interesting. It's from South Africa, and shows a couple of cars of security people taking down a stolen car with occupants. These are NOT police. Apparently, crime is so out of control in South Africa and police are so overwhelmed that heavily armed private security groups have sprung up and hunt down carjackers and thieves with tracking devices on behalf of their clients. They have flashing lights on their cars, and sometimes sirens (though they're not supposed to) and are armed with hand guns, shotguns and automatic weapons. There are a number of these videos, some of them showing them in car chases speeding wildly through the streets in powerful cars.
Go to 6 minute mark to cut out the junk