Worldwide arrests in recent weeks have not managed to dent the resolve of the online group Anonymous.

The hackers’ Italian branch said today that it had blocked access to the Vatican’s official website.

Catholic Church officials said they weren’t sure why their site went down.

Gabriella Coleman, an anthropologist who studies the Anonymous movement and teaches at McGill University in Montreal, says many Anonymous activists do not have sophisticated computer hacking skills, but still participate fully in the movement.

“What sets Anonymous apart is its scale, and depth and breadth,” says Coleman. “Anonymous has managed to spread and circulate in quite monumental ways in part because they’re organizing online.”

She adds, “They’ve certainly captured the imagination like no one else politically in the past year.”