Protests against mass surveillance have now taken to the skies above a major National Security Agency installation.

At about 6am local time on Friday, in a field about a mile from Bluffdale, Utah, two activists from the Electronic Frontier Foundation and Greenpeace launched a 135ft airship and drifted the dirigible over the NSA's massive data center there.

With some cars below entering the center's office park, the lighter-than-air vessel hung a banner reading 'NSA illegal spying below' and a web address for a new EFF site grading members of Congress on their surveillance positions.

It was the maiden patrol of the first anti-surveillance activist air force. While the dirigible, known as the AE Bates Thermal Airship, cannot match the aerial panopticon capability of military surveillance tools like the Argus camera suite – which can see an entire city and record literally decades' worth of video daily – few protest groups have thought to capitalize on the migration of military technologies to civilian life.

Parker Higgins, the EFF activist in the gondola beneath the AE Bates, helped haul the deflated airship from a warehouse in Oakland nearly thirteen hours to Utah. After arriving Wednesday, he and his crew of six others inflated and tethered the airship in an open field near farmland and waited for a window of perfectly calm weather.

"It was surreal," Higgins said shortly after the AE Bates touched down in the same field after flying over and around the Bluffdale center for about an hour.

"The data center is this massive, sprawling complex. I've seen pictures of it, but it's different from the air. You get a sense, really, for the scope of this, the scale of what they're doing there."

Facebook Twitter Pinterest NSA: no comment. Photograph: Greenpeace

At Bluffdale, the NSA is creating an enormous amount of storage capacity – said to comprise around 100,000 square feet's worth, at a cost of over $1bn – for its growing troves of ostensibly foreign-focused intelligence data. A year's worth of revelations from whistleblower Edward Snowden pointed to, among other things, the deep involvement of the NSA in warrantlessly collecting phone, Internet and other data from Americans; and to the NSA's embedding into the firmament of the global internet.

With civil libertarian groups frustrated over the pace and diminished ambitions of surveillance reform legislation, EFF's banner hanging from the AE Bates advertised a new website it launched to assign members of Congress letter grades for their positions on mass data collection. The website also asks President Obama to "to provide a full public accounting of the intelligence community’s mass surveillance practices."

The NSA did not immediately respond to a request for comment about the flight of the AE Bates.

In Utah, the Bluffdale Center has become a libertarian flashpoint within the state legislature. A bill recently introduced to cut off its water supply in protest of the NSA's domestic data troves is expected to receive a full hearing debate by December. One of its supporters, Mike Maharrey of the Tenth Amendment Center, considers it a victory that NSA supporters within the chamber haven't killed the bill outright.

"I feel like it was a good start," Maharrey said.

The flight came right before the Office of the Director of National Intelligence released a long-awaited annual transparency report on the NSA's use of surveillance authorities. One single surveillance order in 2013 for communications data pursuant to a 2008 law encompassed information from over 89,000 "targets affected," the report disclosed.

It further revealed that the NSA was interested in the phone records data of 248 "known or presumed US persons" in 2013 – during which it collected the phone records of practically every American.



Photograph: Greenpeace

While the airship might have flown a bit too early for rush hour traffic to spot it below -- unavoidable, EFF says, because of the specific weather conditions required to fly -- EFF and Greenpeace, which started planning the flight months ago, wanted to be aloft around the July 4 holiday, both for the patriotic symbolism and to nod to a year's worth of post-Snowden activism.

Higgins said he and the crew ensured they would not be flying over restricted airspace. Their airship, naturally, carried no countermeasures should it suddenly find itself with unexpected and irate aerial escort.

"We were making contingency plans for like, what if they scramble fighter jets?" he said, laughing.

"We checked that everything we were doing was legal but the hope is that it's unusual enough to attract attention to what's going on down there."