The other day I covered the spammy structured markup manual action and asked does it result in a ranking decline. I didn't think so, but the community wanted a solid answer from Google.
I had the opportunity to ask John that question yesterday in a Google+ hangout at the 7:12 mark into the video.
I asked, when you get a spammy structured markup manual action, does it downgrade the ranking of the web site or just remove the rich snippets?
John answered, it only impacts the rich snippets. He said:
That is essentially about the rich snippets.Rich snippet themselves don’t give you ranking boosts. So it would’t kind of make sense to demote a site in rankings if they are doing something wrong with rich snippets.
So essentially we just turn off the rich snippets until we are sure that we can trust them.
Here is the video at the start time embedded:
Forum discussion at Google+.