Conard - 9:35 pm on Feb 9, 2003 (gmt 0)

Check out this one line in the article:

For example, Wal-Mart has 1,500 stores scattered across all 50 states, but WalMart.com, a separate subsidiary, has a physical presence in only nine states.

I think that explains the whole thing, they just got caught only collecting sales tax in nine states.