The  has launched a website to allow anyone in the world to ask whether GCHQ has illegally spied on them. However, to find out the information, the group has to share your info with GCHQ and the UK's Investigatory Powers Tribunal.

That tribunal ruled earlier this month that the sharing of mass surveillance data between US and U.K. intelligence services was unlawful before December 2014, because the rules governing this data exchange were secret. This decision allows not only British citizens, but anyone in the world, to ask GCHQ if their records were unlawfully shared by the NSA, the group said.

Want ot know if GCHQ spied on you? Give them yoru details. Image: Ministry of Defence

It's already possible to file a complaint directly with the tribunal by completing and returning a downloadable form. If the tribunal determines that someone's communications were illegally shared with the British intelligence services, it informs the victim. If it finds it has insufficient information to make that determination, it can request more information. Those found to have been illegally spied on can seek the deletion of email messages, phone records, and Internet communications.

Privacy International wants people to send it their details instead, though, allowing it to file a joint claim which it says will streamline the process. While it initially requests only name and contact details, it warns that it may need more information later.

An email address and phone number are probably not enough for GCHQ to find all records. People who want the most comprehensive records searched will probably have to provide much more personal data, including things like an IP address, cookies or a hardware address, Privacy International said.

According to the group, GCHQ is not allowed to hold on to personal details shared with them for other reasons than to establish whether or not they spied on someone illegally and for the duration of the investigation.

It could be a while though before there will be news for those who decide to join the action. As the potential group of interested people is big, it will likely take years before the action is completed, it said.

There's no way to use the process to find out if GCHQ is currently spying on someone, as the tribunal concluded in December that, since the rules governing the exchange have been disclosed, the data exchange is now legal and no longer violates human rights.

The process also only covers data received by GCHQ from the US National Security Agency (NSA), not information passed by GCHQ to the NSA, or information intercepted by GCHQ , Privacy International said.

Loek is Amsterdam Correspondent and covers online privacy, intellectual property, online payment issues as well as EU technology policy and regulation for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to [email protected]

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