When you saw a review from a "Google User" in your Google My Business listings, a local review from a user who has not set up a real Google account, you were able to hover your cursor over that name and it would show you an abridged version of the email address. It would show something like [email protected] and you would be able to use this to help clients or figure out who left that review.
According to the local SEOs in the Local Search Forums this went away a couple of weeks ago and was a very useful feature for local SEOs.
This is what a tooltip looks like by the way:
Ross Dunn said in the thread "As noted above, I consider this a significant loss despite how seemingly small it is. I hope it is restored."
It is unclear if Google intentionally removed it or if this is a bug.
Forum discussion at Local Search Forums.
Update: This should be fixed now.
