The unexpected sign-outs began on Thursday night and continued through Friday, affecting multiple services including Gmail, Chromecast, YouTube, and Google Play.
During routine maintenance, a number of users were signed-out from their Google accounts. This may have resulted in you being signed out of your account or seeing a notification about "A change in your Google account" or "Account Action Required".Google said the issue with its Google Accounts engine also caused some Google Wifi and OnHub devices to automatically revert to factory settings. "Unfortunately, these devices need to be set up again," said Google. "We'd like to share our sincerest apologies for the inconvenience." Instructions on re-setting the Wi-Fi devices can be found here.
We hear your concerns that this appeared to potentially be phishing or another type of security issue. We can assure you that the security of your account was never in danger as a result of this issue.
We know some of you had issues signing in today. Please try again now. Rest easy -- your account's security was not affected.— Google (@Google) February 24, 2017
The reports initially caused some concern among users, coming in just hours after it was revealed that content delivery network CloudFare had been informed by Google of a bug that leaked memory, which could potentially contain private information cached by search engines.
Cloudflare worked with the affected search engines, including Google, Yahoo, and Bing, to erase any remnants of the sensitive data from their caches, and the bug has since been patched.