There is nothing against registering a domain name so long as you aren't representing to be that person. Perhaps the best example is the White House domain problem.
whitehouse.com was registered as an adult website to the chagrin of the government. While it took advantage of an obvious discrepency, it violated no copyrights, or trademarks. The real site is
Home | The White House. Also, Madonna has similar problems years ago when a domain was registered with her name and put up for sale. She claimed that because her name is "unique" no one else should be allowed to use the name because of her fame. The courts said that it was perfectly legaly for someone to register a domain name like that because you can't copyright or trademark a simple name (ie I can't copyright the name James, Jim, Jimmy, etc).