So it appears, as far as Search Engine Journal is reporting, that Google is removing anonymous reviews. And, honestly, why wouldn’t they? If you’re going to write a review you should have the guts to state your first name … or take the time to create a fake profile. At a minimum it will thin the nonsense out a little.
This is being reported only on a couple of sources, so the evidence is thin.
In the tweet from May 24th it was reported that anonymous reviews stopped counting toward the total rating, but were still visible when a user clicked through to see all reviews.
On May 28th it was reported by another user that Google My Business has stopped displaying anonymous reviews altogether.
In any event, if Google does keep counting on anonymous reviews then they should carry less weight, or be kept to one per IP. Some kind of threshold for detecting erroneous reviews should be expected.