Depends. Anybody can sue anybody for anything, right? You need to ask yourself what is your objective doing this. Are you trying to piggyback off the name for your own gain? If it's purpose is a matter of misrepresenting or spoofing someone's "personal brand", say like a celebrity or famous name (Like Alan Hale dot com is expired or is going to, not sure date) a trademark infringement or impersonating someone else that's a problem. Disclaimer if it's parody or tribute, not trickery. But registering a common name JohnSmith.com is so generic- hard to dispute. Just like dictionary words, but people do file UDRP's on them too.