I don't think Arrington is particularly credible nor do I believe Google, as a matter of course and policy, runs around reading specific users' emails. But the comparison to Enron is not necessary for something like this to at least conceivably have happened. After all, this happened
http://www.wired.com/threatlevel/2010/09/google-spy/
I tend to believe Google's GC and think Arrington is having some paranoid attention-seeking fantasy. At the same time, can some schmoe at Google read a gmail email? It seems like they can.