A collective set up by two privacy campaign groups has launched a mass claim against telecoms provider Odido following February’s massive data leak.

Private information, including bank account numbers and ID details, about some 6.2 million people in the Netherlands was stolen during the hack. That information was later leaked onto the dark web by the hackers after Odido refused to pay a ransom.

Consumers United in Court (CUIC) claims the case is the first to be launched against Odido.

The foundation says it hopes to achieve three things through the case: damages for those affected, to set an example to other companies, and to establish how the “enormous data leak” could happen. In particular, the foundation wants to establish why a warning from software maker Salesforce was ignored.

“The company kept far too much information for too long,” CUIC said. “The volume of stolen data shows that it was not properly protected. Odido was not sufficiently transparent and did not report the problem properly.”

People affected by the hack can sign up to participate in the claim without costs. That means part of any eventual financial payout will go to the company financing the legal case.