Google Starts Penalizing Sites for Rich Snippet Spam

If you use rich snippets on your websites, you should be aware that Google is now penalizing websites for spamming structured data markup.

The new warning was first mentioned in a forum post on the Google Webmaster Central forums from a user who is asking for clarification about the warning and what the issue could be. It is a manual action penalty based on incorrect usage of markups, regardless of whether it was deliberate spam or simply a mistake.