Twitter says it “inadvertently” collected iOS location data from some of its users and shared it with one of its “trusted” advertising partners — marking the fourth time in the past year that people’s private information has been made public.

“You trust us to be careful with your data, and because of that, we want to be open with you when we make a mistake,” said the social media giant in a blog post Monday.

“We have discovered that we were inadvertently collecting and sharing iOS location data with one of our trusted partners in certain circumstances. Specifically, if you used more than one account on Twitter for iOS and opted into using the precise location feature in one account, we may have accidentally collected location data when you were using any other account(s) on that same device for which you had not turned on the precise location feature. ”

The company claimed that the data leak had been caused by a “bug.”

“We have confirmed with our partner that the location data has not been retained and that it only existed in their systems for a short time, and was then deleted as part of their normal process,” it said. “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.”

Twitter said it had “intended to remove location data from the fields sent to a trusted partner during an advertising process known as real-time bidding.”

“This removal of location did not happen as planned,” the company explained. “However, 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. The partner did not receive data such as your Twitter handle or other unique account IDs that could have compromised your identity on Twitter. This means that for people using Twitter for iOS who we inadvertently collected location information from, we may also have shared that information with a trusted advertising partner.”

There have been at least four Twitter data bugs reported by the company since September 2018, with the most recent coming in January — when its Android app accidentally made some users’ private tweets visible to everyone. The issue was said to have been fixed.

This story originally appeared in the New York Post.