We are still a good five or six years away from the point where Google would have to worry about alienating the users whose data they sell
I imagine MySpace were saying something similar for a couple of years as Facebook started really taking off, and Yahoo probably thought no new search engines were a threat a year or two before Google arrived.
The Internet is a funny place. A lot of Internet users move in herds, which means a disruptive newcomer can grow very fast if the whole viral networking effect kicks in, but usually when that happens one or more established players must fall to create the space.