(NewsNation) — Hundreds of users are filing a legal claim against dating app Grindr, accusing the service of violating United Kingdom data protection laws by sharing information on HIV status with third-party companies for commercial purposes.

The users say Grinder provided private information, including HIV status and the date of their last HIV test, to advertisers without consent.

Grindr, which began as a hookup app for gay men, now bills itself as a leading dating app and social network for the LGBTQ+ community. The U.S.-based company has millions of users worldwide.

The claim focuses specifically on two periods of time: before April 2018 and between mid-May 2018 and April 2020.

In April of 2018, Grindr said it would stop sharing HIV information after a report from Norwegian researchers found it was sharing data with third-party companies that were designed to monitor user experience and improve the app. Grindr said the practice was in line with industry standards and that it had never shared HIV information with advertisers.

In 2021, the Norwegian data protection authority found Grindr had violated the European Union’s General Data Protection Regulation, though the court did not focus on HIV status. It found that simply joining Grindr could be considered sensitive information due to the stigma faced by the LGBTQ+ community. The authority fined the app more than four million dollars.

Grindr has appealed that decision. The company has been reprimanded in the past by the UK’s data protection authority for its policies.

A Grindr spokesperson told The Guardian it is committed to following data privacy regulations and called the claim a “mischaracterization” of past practices.