It's Al Gore.
Well, not actually Al himself, but the intellectual homogeneity he represents.
When Al shows up and gives his global warming stump speech, he has the Googlers eating from the palm of his hand. They just love the guy.
So, what's the problem with that? Just this: Google has hired too many non-skeptical group-thinkers. If, in a group of 5000 engineers, there is a vast majority who accept Al Gore as a credible source of environmental science, something is wrong. Very, very wrong.
Engineers should naturally be able to see through this William Jennings Bryan of eco-alarmism. If they bothered to look at Peter Norvig's blog or actual temperature data, they might draw less extreme, more scientifically valid conclusions.
The biggest threat to Google is internal. The love affair with Al Gore is a bad sign that too many of their people don't bring enough intellectual diversity and skepticism to the table.