I've heard reports like that too, but from newsreaders, not knowledgable sources. Another poster earlier mentioned that over 250 knots was illegal under 10,000 feet.
That being said, it's possible the plane was going faster if the speculation is true that the pilots were attempting an energency acceleration to stabilize the plane.
I'm just waiting for the facts.
This is not an urban legend. A guy was killed in the WTC. Yesterday, his family's home was hit by the airliner and was burning up. My sister in law is friends with the guy's Florida relatives. The Florida relatives had to fly up there again. If they set up a foundation in conjunction with a benefit, I will post the address in the Florida locale.