I've look this up for myself. Never been told about one. I've usually kept my stutter to myself even though it's obvious, so I guess people choose to ignore it. I've resolved to be upfront about it from now on though. Most of these celebrities either have really minor stutters (Stossel is one) or it kind of went away when they were younger (I think Emily Blunt), so it's kind of irrelevevant. There are a few exceptions though.