Blimp protest over NSA data centre in Utah

Three activist groups flew a blimp bearing the words "Illegal Spying Below" over the US National Security Agency's data centre in the state of Utah in protest against the federal government's mass surveillance programmes.

The 41-metre blimp flew over the hi-tech facility for an hour.

It was launched by the environmental group Greenpeace, which owns it, digital rights activists the Electronic Frontier Foundation and a conservative political organisation, the Tenth Amendment Centre.

An NSA spokesman declined to comment, but noted there was no restricted airspace over the data centre, housed in the grounds of a Utah National Guard camp.

The blimp protest coincided with the launch of an online campaign that rates members of Congress on actions the activists say either further or stop data collection efforts by the NSA.

On Friday, the agency for the first time released data on the scope of some of its most sensitive foreign intelligence-gathering efforts, saying it had targeted nearly 90,000 foreign persons or organisations for surveillance through US companies last year.