At least the State of New York says so:

Advertisements claimed falsely that the coins — which depict the proposed new Freedom Tower" on one side and a Manhattan skyline including the World Trade Center Twin Towers on the other — were made with pure silver and implied they could be used as real money, Spitzer said. "This product has been promoted with claims that are false, misleading or unsubstantiated," Spitzer said in a statement. "It is a shameless attempt to profit from a national tragedy."

National Collector's Mint, who sells the coins, has taken down the product pages on their website, but you can see a cached version here. NCM says that the coins are government issued, just not by our government. The coins are issued by the Commonwealth of the Northern Mariana Islands, an island chain in the Pacific with about 70,000 residents. If you ever plan to go there, this one dollar coin, purchased at half price of only $19.95 via TV, will probably buy you a soda. Here are both sides of the coin itself, you saw them here first. First the obverse, then the reverse.

love it, hate it, there's more of it at Pacetown.