Twitter has recently acknowledged a very convenient bug that allowed the company to collect the location of iPhone users and then share it with an unnamed partner.

Twitter says the problem was discovered on devices where more than a single account was configured. If users enabled the location services for one specific account, Twitter actually collected the data for all accounts configured on the device.

The company says this data was shared with a “trusted advertising partner,” which typically uses such data to display more relevant ads to users.

Twitter says it implemented a feature that partially resolved the issue before releasing a full fix.

“We had implemented technical measures to “fuzz” the data shared so that it was no more precise than zip code or city (5km squared). This location data could not be used to determine an address or to map your precise movements,” it says in a statement.

No other details shared with partner

The unnamed partner did not receive any other data associated with Twitter accounts, such as IDs, passwords, or anything like that. The location was the only one exposed, Twitter says, and the data was only stored on the partner’s servers “for a short time.” It was then deleted as part of the normal process, it says.

“We have fixed this problem and are working hard to make sure it does not happen again. We have also communicated with the people whose accounts were impacted to let them know the bug has been fixed. We invite you to check your privacy settings to make sure you’re only sharing the data you want to with us,” Twitter says.

iPhone users are obviously recommended to update to the latest version of the Twitter app (7.50), which is available from the App Store using this page.