A few weeks after he published a major story about Google, he claims, his source from within the company told him that he (or she - Arrington refused to state the source's gender) had been asked by Google if he were the source. When he denied any knowledge of it, he was shown an email that proved that he was indeed the source.
"The source had corresponded with me from a non Google email account, so the only way Google saw it was by accessing my Gmail account," says Arrington. "A little while after that my source was no longer employed by Google."
He admitted later in the comments that it's possible that the source lied, or that Google might have gotten its hands on the email by sniffing packets on its campus, or that it accessed the source’s non-Gmail account through his (or her) work computer.
His claim was additionally shot down by Kent Walker, General Counsel at Google, who took to the comments section of Arrington's blog to state that while Google terms of service might legally permit such access, they have never done this and that it is hard for him to imagine circumstances where they would investigate a leak in that way.