Is the argument , because the can buy them on the street no one should be checked ? That does not work for me cus every law can be broken so why have them .
This is a completely wrong headed argument.
Obviously someone thinks that laws are a supposed to be a mechanism to "prevent" crimes. This is simply unrealistic.
Laws serve two functions, they guide the law-abiding person so he does not break the law. And they serve as justification to punish those who do break the law.
But in and of themselves laws can not prevent a criminal act, if they did, there would be no crime