Google Adsense publishers have suddenly started receiving the following email since past few days, as you can see the content of the email is not very reader-friendly with the text being

We have now verified that we are no longer detecting PII being passed to Google from the account(s) under your control.

. This even makes things more complicated as in my case (as well as majority of others reported on webmaster forums) I had not received any previous policy violation warning earlier which Google is now intimidating of being cleared off.

Upon some research I found this particular warning is sent to publishers passing "Personally Identifiable Information (PII)" on their website and/or apps, the official explanation can be found here - https://support.google.com/adsense/answer/6156630?hl=en. However, if a publisher is found to violate this policy they are sent the below notice:

Dear customer:

It has come to our attention that you are passing personally identifiable information (PII) to Google through your use of one or more of Google\'s advertising products -- DFP, AdSense, and/or Doubleclick AdExchange.

Our systems have detected PII, including email addresses and/or passwords, being passed from each of the domain names below. We have also included below an example of an ad request that we received from your account (from which the PII detected has been redacted).

Our contracts and policies prohibit information being passed to us that we could use or recognize as PII. Sending us PII has put you in breach of those terms.

You should review your implementation of Google tags on your pages, including whether PII of any nature may feature in the URLs of such pages.

Please give this matter your immediate attention. You should submit your response in this form.

If you fail to achieve compliance with your contract within 30 days we may disable ad serving on your account(s). If you fail to submit any response within 14 days, access to your account will be suspended.

Domain names at issue:

Since, the first notice makes sense only if the above is received and almost all publishers are suddenly receiving the first notice now without receiving the policy-violation warning, it seems this is most probably a software glitch at Google's end which is sending these emails.

Update : As anticipated above this was an erroneously sent email, Google sent a followup explanation as below:

Dear Publisher

Google recently sent you an email in English from publisher-policy-no-reply@google.com, with the subject of "policy breach notice," regarding personally identifiable information.

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.

As you know, our policies prohibit partners from sending us data that could be recognized or used by our systems as personally identifiable information. When we learn of violations, we notify the publisher and take swift action.

We know that you take user data and our program policies very seriously, and this message must have caught you off guard. For more information about the specific policies that govern passing PII to Google, and tips for continuing to keep your account compliant, please visit our help center.

Thank you,

Stephen, Amy, Geoff and Rebecca
Google Publisher Policy Team

Google Inc. 1600 Amphitheatre Parkway, Mountain View, CA 94043

You have received this mandatory email service announcement to update you about important changes to your AdSense or DoubleClick product or account.