I'm afraid people are getting libertarianism confused with either purely social and civil liberty OR they think it sounds better than saying I'm a Big Government Liberal who thinks we need to live in a Nanny State or they're dumb (not mutually exclusive with the former choices) and think it means liberalism.
By the way, anyone who has not seen it, should go to youtube right now and search for "The Money Hole." This was a special done by John Stossell back in June. It's truly fantastic. Several people have posted the entire show together and in segments for easy digestion. The entire show is based on this sketch from TheOnion.com