In early April, some Twitter users began seeing an update atop their feeds, reading, “An update to your data-sharing settings: The control you have over what information Twitter shares with its business partners has changed. Specifically, your ability to control mobile app advertising measurements has been removed, but you can control whether to share some non-public data to improve Twitter’s marketing activities on other sites and apps. These changes, which help Twitter to continue operating as a free service, are reflected now in your settings.”
A Twitter spokesperson clarified at the time that the change affects a data-sharing setting relating specifically to mobile applications measurement, and it applies globally to all users except those in the European Union, European Free Trade Association states and the U.K., in order to comply with the General Data Protection Regulation.
The social network further elaborated last month: “Twitter shares certain non-public personal information with advertisers who run mobile app advertising campaigns through Twitter. This information can include which ads a particular browser or device saw, watched or otherwise interacted with; but it does not include your name, email, phone number or Twitter username. For example, Twitter might share that a mobile device identifier viewed or clicked on an ad for a particular mobile application.”