Google has announced that they are closing the consumer functionality of Google+ due lack of adoption and an API bug that leaked the personal information of up to 500,000 Google+ accounts.

While no evidence was found that indicates this bug was ever misused, it was determined that the complexity of protecting and operating a social network like Google+ was not a worthwhile endeavor when so few users actually used the service for any length of time.

"This review crystallized what we’ve known for a while: that while our engineering teams have put a lot of effort and dedication into building Google+ over the years, it has not achieved broad consumer or developer adoption, and has seen limited user interaction with apps," stated a blog post by Google regarding the Google+ closure. "The consumer version of Google+ currently has low usage and engagement: 90 percent of Google+ user sessions are less than five seconds."

The consumer functionality of Google+ will be closing over a 10 month period, while Google transitions the product to be used internally by the Enterprise.

API bug caused data leak

After performing a code review of the Google+ APIs, called Project Strobe, Google stated they discovered a bug that could leak the private information of Google+ accounts. This bug could allow a user's installed apps to utilize the API and access non-public information belonging to that user's friends. The non-public information that was accessible includes an account holder's name, email address, occupation, gender and age.

Underlining this, as part of our Project Strobe audit, we discovered a bug in one of the Google+ People APIs: Users can grant access to their Profile data, and the public Profile information of their friends, to Google+ apps, via the API.

The bug meant that apps also had access to Profile fields that were shared with the user, but not marked as public.

This data is limited to static, optional Google+ Profile fields including name, email address, occupation, gender and age. (See the full list on our developer site.) It does not include any other data you may have posted or connected to Google+ or any other service, like Google+ posts, messages, Google account data, phone numbers or G Suite content.

We discovered and immediately patched this bug in March 2018. We believe it occurred after launch as a result of the API’s interaction with a subsequent Google+ code change.

As Google only keeps two weeks of API logs for its Google+ service, it was impossible for them to determine if the bug was ever misused. They were able to determine that the bug was not misused during the two weeks that they had log data.

Google knew about leak in May but did not disclose

According to a report by the Wall Street Journal, the bug in the Google+ API existed between 2015 and March 2018, which was when Google discovered and fixed the bug. According to their reporting, an internal committee at Google decided not to disclose the bug even though they were not 100% sure that it was not abused.

The Wall Street Journal, reported that they have reviewed a memo prepared by Google's legal and policy staff, which indicated that disclosing the data breach could lead to scrutiny by government regulatory agencies.

"disclosing the incident would likely trigger "immediate regulatory interest" and invite comparisons to Facebook's leak of user information to data firm Cambridge Analytica."

In a statement to BleepingComputer, a Google Spokesperson said that their Privacy & Data Protection Office felt it was not necessary to disclose as it did not meet the threshold that would warrant it.