Spanish police announced on May 17, 2008 the arrest of at least four members of a Spanish speaking group called D.O.M. This group is alleged to be one of the more prolific web defacement groups in the world. Spanish police estimate they were responsible for as many as 21,000 attacks on websites - most as political protests:
"Some of the more high-profile attacks credited to the group, at least from an American perspective, would include having hit the US government's National Cancer Institute with an SQL injection attack back in July of 2007, ( archived from Zone-H). In February, an0de defaced an MIT server with an anti-American, anti-Bush message, archive from Zone-H ."
Spanish Arrest D.O.M. Team