If your friend is in the USA, he will find that employers have to report/verify each employee to the government. I think it depends on each state. but my state requires that each employer has to input every new employee with name/soc.security/etc. the main reason is to make sure that they are legal residents. So, just having a fake id is probably not enough. I don't know how hard it is to fake a social sec. number but im sure its being done because I know of a lot of illegals that still get into the system.