How do you feel about the banning of so called "dangerous" dog breeds?

For example, for the most part it is illegal to own a Pit Bull Terrier in the UK. I am completely against the banning of whole breeds (blame the DEED not the BREED) and think we should focus more on vetting potential dog owners rather than just allow anybody to buy a dog (or any animal for that matter). I have dogs myself and would happily pay a license fee to keep them if there was any chance that the idea of paying a licence fee would deter anyone who wants a dog for the wrong reasons. What are your thoughs on this?