Privacy International has revealed how GCHQ has been building a database of UK citizens' private information for more than 15 years with the full approval of successive governments.
The information was revealed in a series of documents after the campaign group won a court case against the spy agency.
Privacy International said that the documents go back to 1998, and show details and memorandums about a range of information, including passports and text messages. GCHQ has admitted that most of the personal information has no operational value.
"The papers released today act as proof of, and show the sheer scale of, British intelligence agency surveillance of our personal data," said Privacy International.
"It goes far beyond monitoring our text messages, email messages and social media posts. The intelligence agencies have secretly given themselves access to potentially any and all recorded information about us.
"The documents reveal the potential to requisition medical records and confidential information shared with a doctor (including blood group, physical characteristics (hair/eye colour), biometrics, travel records, financial records, population data, commercial data (details of corporations and individuals involved in commercial activities), regular feeds from internet and phone companies, billing data or subscriber details, content of communications (including with lawyers, MPs or doctors) and records from government departments."
Privacy International said that there are hundreds of millions of records at GCHQ's disposal. V3 has asked GCHQ for its response to the release but it has not yet responded. Privacy International, however, has been much more forthright.
"The information revealed by this disclosure shows the staggering extent to which the intelligence agencies hoover up our data. This highly sensitive information about us is vulnerable to attack from hackers, foreign governments and criminals," said Millie Graham Wood, legal officer at Privacy International.
"The agencies have been doing this for 15 years in secret and are now quietly trying to put these powers on the statute book for the first time in the Investigatory Powers Bill which is currently being debated in Parliament.
"These documents reveal a lack of openness and transparency with the public about these staggering powers, and a failure to subject them to effective Parliamentary scrutiny."
The disclosures today provoked swift condemnation from many in the IT industry who believe that overbearing secret services are undermining the sector.
"The UK government and its intelligence agencies are watching UK citizens as if they were criminals," said Jacob Ginsberg, senior director at email encryption firm Echoworx.
"This kind of cyber surveillance is no different to old-school wire-tapping. However, a wiretap may be approved by a court only if evidence of reasonable suspicion can be found.
"The government should not be allowed to circumvent existing laws that have been put in place to protect law-abiding citizens from potentially harmful intrusion.
"Having the power to sweep someone's phone records, financial data, medical records and internet communications without a warrant during bulk data collection is morally wrong."
The Privacy International release conforms with earlier information released by Edward Snowden, but goes much further in demonstrating how widespread and intrusive GCHQ's surveillance and information gathering has become.
V3 will report the official response from GCHQ and the government over these disclosures when we get it.
GCHQ admitted recently that it has been losing the cyber security battle on which it has spent at least £1bn.
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