SLF here, very experienced traveller flying man and boy since 1962, no connection to the industry. I always keep my seat belt fastened. I have flown many carriers including US carriers, most recently UK to the US on Continental. I have noticed the tendency on these flights and other US carriers for the pilots to "cry wolf". For the most mildest of turbulence, I get more driving my car, the seatbelt sign goes on and what is more left on for ages after the few "slight bumps" (Continental pilot's words, not mine). By ages I mean in one case up to an hour and a half. Guess what? Passangers are ignoring the sign, going to the loo, walking around, getting hand baggage and so on. I do not find Australian, British and other European or S.E. Asian pilots putting on the seat belt sign unless it is needed, and it very definitely is needed in those instances. Unexpected events can occur, I accept that, but US pilots are endangering passangers if the latter come to believe the seat belt sign is on for no reason. And my experience is that travellers on American carriers are beginning to ignore the sign because absolutely nothing is going on in terms of turbulence for most of the time the sign is on. I am fully aware of the risk averse nature of American business these days so as to prevent law suits (I am a lawyer) hence the cautious nature of pilots to turbulence. However any risk assessment must involve a balancing of interests including the tendency of human beings to think he, the pilot, is "crying wolf".