British intelligence agency Government Communications Headquarters (GCHQ) may have been collecting personal social media data of people as part of their mass surveillance efforts.

According to an Engadget report, the GCHQ has been collecting such information over years, even decades, and has been sharing this information with foreign intelligence and other law enforcement agencies. The Investigatory Powers Commissioner's Office (IPCO), the body that oversees the activities of the GCHQ, has also been reportedly left out of the loop with regards to this.

However, it is still not clear to what extent the data is being collected and what it is being used for. What kind of data is getting collected is also yet to be revealed. GCHQ, it is reported, obtained the information through databases from private companies.

The data has been categorised into biographical data, financial activities, travel, and more.

This is not the first time a government has been found collecting social media data of its citizens. In September, it was reported that the CIA was developing AI to track and gather intelligence.

Privacy International (PI), a privacy watchdog, was reported to have documents that support these claims. It was also reported that the GCHQ has too much data for it to actually analyse it fully. PI is apparently questioning the British government's overreach in using its investigatory powers to gather mass surveillance data and then share it.

It was also reported that the GCHQ has too much data for it to actually analyse it fully. PI is apparently questioning the British government's overreach in using its investigatory powers to gather mass surveillance data and then share it.

"This is the first time on record we know bulk personal data sets contain social media data and sensitive medical records," said Millie Graham Wood, a solicitor at PI.

"To know they have large-scale social media data on an untargeted basis is pretty shocking. We don't know how long it's been going on for, or whether it's shared with foreign governments, industry and other departments like HMRC (Revenue and Customs). If you think about how sensitive social media data are, it's so dangerous if there is no oversight."

According to Financial Times report, an investigation was conducted in August and September and an audit of the data was made on all the files held by intelligence agencies like the MI5, MI6 and GCHQ.

The audit, it was reported, found that they had "sensitive medical data or financial details" apart from social media information.

Both Facebook and Twitter have denied that the social media information did not come from their platforms.

"We have just started our audit process and will continue to do a series of inspections on whether [intelligence agencies'] practices are lawful or not," an IPCO spokesperson said.

It remains unclear with which countries and governments the data have been shared. The FT report says that it is also not clear if this sharing is part of the "Five Eyes" intelligence community that comprises of UK, USA, Canada, Australia, and New Zealand.