As others have indicated, credit rating agencies are not permitted to blacklist a person SOLELY because of their address.
However they have every right to do so when they believe that there is a 'financial association' between the person who is applying for credit and the person who has a poor credit history. An obvious example is when they believe that two people, sharing the same address, are living together as sexual partners, rather than just as flatmates. The agencies also tend to assume that members of the same family, at the same address, have a 'financial association'. So you might well (unless you do something about it) find that your own credit rating is adversely affected by your son's poor credit history.
You joke about 'disowning' your son but (in the financial sense only!) that's exactly what you need to do. You should file a 'notice of disassociation' with at least one of the three main credit reference agencies. (It's probably best to do it with all of them, but they usually share information anyway). The agencies are Equifax, Experian and CallCredit.
Chris