From zdnet.com
Impacted users include only those who clicked or viewed an ad for a mobile application and later interacted with that mobile application.
The exposure data was from May 2018 to August 5, 2019, when it discovered and fixed the bug.Twitter said the bug resulted in sharing some user data — such as country code, device type, and ad details — with a select list of advertisers Twitter uses for ad tracking and measurement purposes.
Twitter shared the full list of user ad data it exposed, and the the list of ad partners who may have received the info, but it did not disclose the name of the mobile apps which advertised on its platform and triggered the bug.”We know you will want to know if you were personally affected, and how many people in total were involved,” Twitter said.