I saw the same thing a few weeks ago when I was in a hotel in Tampa. I saw the hotspot, and was thinking to myself 'Oh, the hotel has a free public wifi hotspot, sweet!', and then slowly noticed that after connecting that it was ad-hoc and rather useless for anything. I then figured that it was just some punk with a laptop who was trying to lure other laptop users into connecting to his machine for some malicious purpose or another, and was glad that my little linux tablet probably wouldnt be too vulnerable. I didn't think much of it, but now that you bring it up I have a bit more faith in humanity that it was a windows 'feature' rather than just another wannabe hacker. Go figure I always assume the worst.