Anti-surveillance activists flew a blimp above the National Security Agency’s massive, $1.5 billion data center in Bluffdale, Utah on Friday as an act of protest against the NSA’s contentious collection of vast amounts of the world’s digital data.

The airship belongs to the environmentalist organization Greenpeace and was flown early Friday over the NSA’s newly completed data center as a demonstration waged collectively by that group and the Electronic Frontier Foundation, a California-based advocacy group that defends digital rights and has fought tooth-and-nail against the United State intelligence community’s surveillance programs since before former contractor Edward Snowden began to leak classified secrets about those operations last year. The Tenth Amendment Center, “a national think tank that works to preserve and protect the principles of strictly limited government through information, education and activism,” also participated in the unannounced flight.

Blimp flying near NSA facility this morning. #utpolpic.twitter.com/nBVxQU71um — David Lifferth (@DavidLifferth) June 27, 2014

On Twitter, the EFF said the event was being conducted to announce the organization’s “new campaign grading Congress on surveillance reform,” now online at StandAgainstSpying.org.

“The goal of the congressional scorecard is to raise public awareness about the surveillance debates taking place right now and to create public pressure on individual members of Congress and the president to take significant steps to reform NSA spying in light of the information the public has learned over the past year,” the website reads in part. “We aim to stop any bills that would codify mass surveillance while at the same time bolstering support for meaningful surveillance reform.”

Previously, legal counsel at the EFF has represented plaintiffs in several cases waged against the NSA’s data collection policies, including litigation that began before and after last year’s Snowden revelations.

Parker Higgins, an activist with the EFF, told KSL’s Doug Wright early Friday that the blimp was loaded in a trailer and hauled from California ahead of the early morning launch. Flight restrictions, Higgins said, prohibited the groups from getting the blimp airborne until after 7 a.m.

Soon after, however, the airship’s presence in the Bluffdale airspace was unavoidable and passersby snapped photographs that quickly circulated widely on the web. According to Higgins, the number of cars seen pulling over to watch the blimp as he viewed from above gave him the impression that the stunt “ended up making the splash” that the groups had hoped for, and with, so far, no negative repercussions.

"We checked in advance that everything was legal," Higgins told KSL, acknowledging that the flight brought the Greenpeace and EFF-chartered blimp quite close to the US National Guard’s training center at nearby Camp Williams. The NSA center itself, according to blueprints previously published by Forbes, encompasses around 100,000 square feet.

"At least for now, thumbing your nose at the government is not illegal,” Higgins added. “We did not break the law."

Taking a selfie with @GreenpeaceUSA above the NSA data center in Utah was definitely necessary. More pics soon! pic.twitter.com/A1Q9ZgjAve — EFF (@EFF) June 27, 2014

Previously, however, others with an interest in seeing the Bluffdale data center from the air ended up on the radar of law enforcement soon after. When Fox News rented a helicopter to flight over the facility while it was still being constructed in 2012, the chopper’s pilot was visited by federal agents two weeks later on a "national security matter.”

"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,” Higgins told Spencer Ackerman at The Guardian after Friday’s flight.

Friday’s flight also coincided with the US Office of the Director of the National Intelligence’s publication of details pertaining to the use of national security authorities to collect digital information — endeavors that are indeed opposed by the EFF and other anti-surveillance groups.