[jpl]

If it is Islamofascists, then we must ask, Why Spain? IMO, because GWB and particularly John Ashcroft have made it too difficult for them to do it here again.

Also, I'd add that

1) Spain has been a staunch ally of the U.S. in our war against the terrorists.
2) Spain used to be under Muslim control centuries ago, and the Muslim extremists feel that they're entitled to try and regain permanent control of any lands that they once held by any means necessary.

[B Knotts]

You are correct. Remember that in one of his rambling screeds, bin Laden mentioned the "tragedy of Andalusia."

Yeah, it could be ETA, but I doubt they would be denying it if it was. That ain't their M.O.