The Irish Council for Civil Liberties has said it is filing a GDPR lawsuit in Germany against the world's online advertising and data broker industry.
The ICCL said the lawsuit takes aim at Google, Facebook, Amazon, Twitter, Verizon, AT&T, and the entire online advertising and tracking industry, by challenging industry rules.
It said the lawsuit challenges the data broker industry’s rule book, called the IAB Audience Taxonomy, which it said allows data brokers and online advertising companies to build dossiers about individuals based on the online sites they visit.
Dr Johnny Ryan, Senior Fellow of ICCL who is filing the lawsuit, said these dossiers can include details about things like your mental health condition and your financial situation.
"These secret dossiers about you, based on what you think is private, could prompt an algorithm to remove you from the shortlist for your dream job," he said.
"A retailer might use the data to single you out for a higher price online.
"A political group might micro target you with personalised disinformation," he added.
ICCL said it is going to court to challenge this system, and the online advertising industry which it said feeds that system.
Mr Ryan also said that 'Real-Time Bidding' (RTB) - a practice that allows data brokers to build profiles of individual users based on private things they do online - is a central target of ICCL's lawsuit.
Though RTB data can contain very sensitive information, the ICCL said that industry documents also confirm that there are no technical measures to limit what companies can do with this information, nor who they pass it on to.
Mr Ryan claims that this is a data breach which happens hundreds of billions of times a day - according to industry documents cited in ICCL’s evidence.
Defendants include the Interactive Advertising Bureau (IAB), which sets the rules that govern Google and Facebook and the entire online advertising industry.
The ICCL said it wants this lawsuit to force the online advertising industry to stop tracking people online.