The U.K. government reserves the right to snoop on citizens' Facebook, Google, or Twitter activity because officials do not need a warrant to intercept communications conducted outside of Great Britain, new data has revealed.

Since Facebook, Google, and Twitter (among others) are U.S. companies, messages posted to those services are deemed "external communication," Charles Farr, director general of the Office of Security and Counter Terrorism, said in a statement provided to Privacy International, which is suing the government for what it considers to be illegal surveillance tactics.

He pointed to Google, which runs a number of international data centers, the largest of which are in the U.S. and otherwise outside of the British Isles. If an individual in the U.K. types a Google query, the site automatically communicates with servers in foreign countries, or "external communications," as Farr put it.

And since the U.K.'s Regulation of Investigatory Powers Act (RIPA) does not require a warrant to intercept external communications, TechCrunch pointed out that it is legally justifiable for spy agencies like the Government Communications Headquarters (GCHQ) to harvest Facebook updates, tweets, or YouTube searches.

Farr's 48-page document—signed and dated May 16—marks what the BBC said is the first time the government has publicly commented on how it understands the U.K.'s surveillance laws apply to mass interception.

According to Privacy International's legal complaint, GCHQ and the NSA are "infecting potentially millions of computers and mobile devices around the world" with harmful software that allows them access into people's lives.