Over the first 2 weeks of March 2017 I have been noticing more and more sites losing their review stars in Google search. The stars have legitimate uses but are typically used by attorneys and law firms to gain attention in search results. I wrote about how they get the stars here.
A look at the Mozcast confirms that I am not crazy. Here is a screenshot showing the percentage of search queries producing review stars in search results decreasing.
There is no real clear guidance from Google if they should or should not be used. I did ponder here that aggregated reviews are probably considered spam, and I also predicted here that Google would likely “fix” this in 2017.