Thay claimed their 15 minutes of fame earlier
http://www.ourjerusalem.com/arabpress/story/arabpress20030821.html
Al-Qa'ida Claims Responsibility for Last Week's Blackout
MEMRI August 19, 2003
Al-Qa'ida's Abu Hafs Brigades has claimed responsibility for "Operation Quick Lightning in the Land of the Tyrant of this Generation," referring to the blackout last week in the Northeast and Midwest United States. A communiqué by the Abu Hafs Brigades was published at
http://groups.yahoo.com/group/abubanan2/message/330. This is the third communiqué by the "Brigades" that is being published by the same web-group; in the first, they accepted responsibility for the downing of an airplane in Kenya. The second accepted responsibility for the Jakarta bombing of the Marriott hotel on August 5, 2003.
The new communiqué says that in compliance with the orders of Osama bin Laden to strike at the American economy, the Brigades struck two important electricity supply targets on the East coast. The Brigades say that they cannot reveal how they did it, because they will probably have to use the same method again soon. The communiqué also claimed that the operation was meant as a present for the Iraqi people.