Yesterday we reported how tons of Google AdSense publishers received breach notices over PII (personally identifiable information). Well, that email was sent in error.
Google's Policy Team posted in the Google AdSense Help forum apologizing, calling it an error. They wrote:
This weekend the Google Ads Policy system inadvertently sent publishers a message informing them that they had resolved a violation of the Identifying Users policy, or that Google had not seen PII sent from their account for a certain number of days.
The message was sent in error; we would like to convey our sincerest apologies for the alarm that this must have caused you and your colleagues.
You do not need to take specific action on this erroneous message however, due to the dynamic nature of publisher monetization we encourage you to periodically review our resources regarding PII.
So if you received the email, I'd just trash it and go about your day - if you haven't done so already.
Forum discussion at Google AdSense Help.