For one, cars and trucks are licensed, visibly. If a license were required for a gun, it would be too small for most people to see and if it was an RFID tag, I would bet that privacy concerns would be raised because it could be scanned from a distance through the act of someone in Law Enforcement when it's concealed. While I like this in the event that someone is in possession illegally, I don't really like it as a private, law-abiding citizen. If this could be done in a way that it can't be easily defeated, it would make finding lost, ditched or stolen guns a lot easier.

We are required to make notice when we sell a car or truck, but it's pretty hard to hide one, unlike a handgun. Yes, people use cars when they commit crimes, they aren't usually the weapon of choice. OTOH, people buy and sell cars without telling the DMV, all the time. Usually, the title isn't signed and it could go through several buyers before someone totals the car, steals it or abandons it- these cars tend to be priced low because they're used as a disposable item- it's cheaper to buy a POS car and drive it until it drops than to spend the cash on a good car, then title it and maintain it. They usually have temporary plates and belch smoke because they haven't been maintained well, if at all. Go to a gas station in a bad area and you'll see people putting $3 worth in because that's all they have.

Illegal guns change hands frequently, too. It's not a good idea to keep one for long and can travel around the country for years before they're revocered or destroyed.

There are no easy or popular answers. Bad behavior is learned by people in circumstances they can't control and it can be justified in many ways. When children are raised around people who can't make a good decision if their life depended on it, they end up in the same position, later.

People need to think before they act, but when their choice is to be the aggressor or be a victim, they'll be the aggressor. People in MKE are really getting tired of the violence, though. I really would like to see them make a difference.