When users and companies promote sponsored tweets on Twitter, they can filter an ad's audience based on a series of criteria.
The problem, Twitter said, was that emails and phone numbers that users provided to be used specifically for security reasons where "inadvertantly" made available for "Tailored Audiences" and "Partner Audiences," two of the company's internal advertising systems.
Twitter said this was a bug, and not something it intended to do. The issue was fixed on September 17, and the company said that no user data was shared with external entities.
"We cannot say with certainty how many people were impacted by this, but in an effort to be transparent, we wanted to make everyone aware," the company said in a short statement posted on its website.
"This was an error and we apologize."
A long list of Twitter platform "issues"
Unfortunately, these kinds of statements and apologies are becoming the norm at Twitter. For the past year, the company has been disclosing similar blunders all over its platform.