Cell Phones and Privacy

I do not think that repaid phones should be banned at all, not should they have to be registered. I understand it would make it easier to track certain criminals, but what about the average citizen that didn't do anything? I have heard of some people getting pre-paid phones because it is cheaper for them or more convenient. Some people also may use them when traveling abroad. Prepaid phones have many uses other than just using them after breaking the law. It would not be fair for the government to be able to track everyone's prepaid phone. If someone buys a prepaid phone they should not be punished due to other buyers who have committed crimes. It just wouldn't make sense.