Back in the earlier days of the SEO industry, there was a mystery Google representative who participated at WebmasterWorld forums under the alias of GoogleGuy. Back then, very few people knew the true identity of GoogleGuy, but yet many speculated his identity.
Then in August 2006, reports came out that Matt Cutts confessed to being GoogleGuy during a session at SES. Danny Sullivan said:
I moderated the panel, and the confession came out when a member of the audience flat out asked Matt if he was GoogleGuy. Matt hesitated just a moment, and I could swear I could almost hear the internal debate of "should I finally confess or not." And then he did, saying as Rand notes that he sort of backed into being the GoogleGuy who posts on forums and blogs. Matt then added that today, GoogleGuy might be one of many different people from Google commenting in public areas.
But if you look at the Wikipedia page for Matt Cutts, it links specifically to this post and Matt said he "was quoted out of context."
To this day, you will not find Matt admitting in writing that he was GoogleGuy. But a comment from WebmasterWorld's founder, Brett Tabke, a person who would know the true identity of GoogleGuy said:
When Matt was on wmw as GoogleGuy for all those years, that is what we had to deal with daily.
He is referring to Matt Cutts as being GoogleGuy. Back in 2006, Danny reported that Brett told him "Matt's been wearing a "Google Guy" name badge at PubCon for the past two years now, and Thomas Bindl notes this was the case last November at the show, as well."
So although Matt has been outed a few times as being GoogleGuy, Matt has never officially come out as the legendary GoogleGuy.
Forum discussion continued at, oh, GoogleGuy hasn't made a post at WebmasterWorld since July 24, 2008.