Ask HN: To Reserve Company and Celebrity Usernames or Not?

If you were starting a service which uses public usernames (similar to Twitter handles), would you reserve a batch of handles for companies and high profile names?

Or is this over complicating things? I've heard some stories about Facebook kicking someone off their facebook URL to give it to a celebrity and backed off due to the PR disaster. Would you just let names go on a first come first serve basis?