Reply #6: Doesn't make sense to me.

[seasat]

FBI officials said the surveillance of the anti-war movement was necessary to prevent protests being used as a cover by "extremist elements" or by terrorist organisations to mount an attack.

If you were a member of a terrorist organization you would probably use a pro war group as cover. You'd attract less scrutiny and be able to get closer to potential targets than the "First Amendment" Gulags.