November 8 (or 9), 2022

Mass Claim against Twitter: Dutch foundation fights illegal sharing by ‘free’ apps

Campaign ‘You are for sale’  will start today

Advertising platform MoPub collected and shared data from thousands of free apps, such as Wordfeud, Buienradar, Vinted, Shazam and Duolingo. According to Stichting Data Protection Nederland (SDBN), MoPub, a service that was until recently owned by Twitter, violated the privacy of millions of Dutch users. SDBN is therefore preparing a class action suit against Twitter and will launch a supporting awareness campaign “You are for sale” (Je staat te koop), to start on November 8.

Mass privacy violations and illegal data trade

Between 2013 and 2021, Twitter, through its advertising platform MoPub, gained access to data from more than 30,000 mobile applications in the Netherlands alone. In addition to Wordfeud, Buienradar, Vinted, Shazam and Duolingo[a], this also concerns numerous fitness apps such as MyfitnessPal, period tracking apps, dating apps such as Grindr and Happn, and games for children such as My Talking Tom. The list is long.

Millions of Dutch people use these kinds of free apps on their phone or tablet. But “free” does not exist in the online world. Consumers paid with their privacy. For years, users were for sale, without ever giving MoPub permission to collect and share their data.

Even those who never sent a single tweet are impacted, as Twitter and MoPub collected information on them via third party apps. Over the course of eight years, they gathered and shared data with thousands of companies and advertisers, while leaving consumers unaware with whom data was shared and for what purpose. Data on a user’s location, on personal traits such as sexual orientation, on personal desires such as wanting to have children, and on religious beliefs of users,  was broadcast by MoPub, and collected and resold in the ‘data broker’ ecosystem.

MoPub and Twitter earned millions with this illegal data trade. They collected much more data than needed and  failed to ensure the security of millions of peoples’ personal data and thus violated the most important law on the protection of personal data: the GDPR.

Compensation and lawsuit

An estimated ten million adults and 1 million children who lived in the Netherlands between October 2013 and December 2021 and who used the free apps, fell victim to this illegal trade in personal data. In practice, it is impossible for individual victims to claim their rights against large parties such as Twitter. That is why SDBN will act on behalf of this group,  through a class action lawsuit. Among others, SDBN demands compensation for harm done.

If Twitter is not willing to come to a solution, SDBN will file a claim in the Netherlands. Users can support the lawsuit by registering via jestaattekoop.nl. Individual victims do not have to pay to participate in this lawsuit. Registering for the lawsuit is necessary to convince the judge that something must be done about this.

The Dutch privacy specialist Anouk Ruhaak, chairman of SDBN, says: “It is clear that privacy has been violated through these types of free apps. The nature and scale of this infringement is dizzying: it happened for years and behind the scenes. As a society, we must show that this is unacceptable and these illegal practices are not allowed to stand. We don’t want to be for sale. We hold Twitter responsible for this type of illegal data collection and demand collective compensation. With Stichting Data Protection Netherlands we stand up for all victims of these privacy violations.”

About Stichting Data Protection Netherlands

SDBN is a Dutch non-profit foundation that is committed to a world in which privacy is respected by companies. SDBN protects the interests of victims of privacy violations. SDBN strives to ensure that citizens become aware of the value of their data and the consequences of data infringements. SDBN wants privacy infringements to stop and demands that victims of violations receive adequate compensation.

Examples of free apps through which Twitter’s MoPub platform collected and shared personal data between October 2013 and December 2021:

  • Shazam – (more than 5 million downloads in the Netherlands)
  • Vinted – (more than 4.1 million downloads in the Netherlands)
  • Helix Jump – (more than 4.2 million downloads in the Netherlands)
  • Wordfeud – (more than 3.8 million downloads in the Netherlands)
  • Trivia Crack – (more than 3.5 million downloads in the Netherlands)
  • Zedge Wallpapers – (more than 3.3 million downloads in the Netherlands)
  • Super-Bright LED Flashlight – (more than 3.1 million downloads in the Netherlands)
  • Picsart Photo & Video Editor – (more than 3 million downloads in the Netherlands)
  • MyFitnessPal – (more than 2.9 million downloads in the Netherlands)
  • Piano Tiles 2 – (more than 2.9 million downloads in the Netherlands)
  • Agar.io – (more than 2.7 million downloads in the Netherlands)
  • 8 Ball Pool – (more than 2 million downloads in the Netherlands)
  • My Talking Tom – (more than 2 million downloads in the Netherlands)
  • Duolingo – (more than 1.9 million downloads in the Netherlands)
  • Badoo dating – (more than 1.6 million downloads in the Netherlands)
  • Solitaire by Zynga – (more than 1.6 million downloads in the Netherlands)
  • Happn Dating App – (more than 1.5 million downloads in the Netherlands)
  • Sudoku.com – (more than 1.4 million downloads in the Netherlands)
  • Buienradar – (more than 1.3 million downloads in the Netherlands)
  • Grindr – Gay Chat – (more than 510,000 downloads in the Netherlands)



For further information, please contact Michel Langendijk, press officer Data Protection Netherlands Foundation at [email protected] and +31 (0)6 4096 3010

Anouk Ruhaak is the chairman of SDBN and a privacy specialist and activist. She previously worked at the Mozilla Foundation. She works in Canada. She is in the Netherlands and available for interviews until November 10, 2022.

Julia Janssen is an ambassador for Stichting Data Bescherming Nederland in the lawsuit against Twitter. Janssen is an artist and researcher and has been committed to privacy and data protection for years. Among other things, she made the video of “You are for sale. In addition to Anouk Ruhaak, Julia Janssen is also available as a spokesperson.