I've received several reports from webmasters that the Google Structured Data report in Google Webmaster Tools is all of a sudden showing a huge drop in the items being reported.
Some are saying they've gone from 3,000 items to 250 or so items being reported in that tool.
Lucas Mayeur from Delegator sent me a screen shot of one of his clients going from 440 items down to 24 items:
Have you noticed a large drop in your structured data items being reported? Check out your Google Webmaster Tools to be sure.
Update: A few days later, some are reporting the numbers are back to normal.