Identity Theft: Michael Arrington vs. Seth Godin?

So there is a lot of mention about the use of identity theft related to malware and financial account fraud. There is no question that this is a big problem, but there are some precautions that one can take to lessen the risk. However, as I read the spat between Michael Arrington and Seth Godin that appears in the comments (#11 & #15) of a recent TechCrunch article, it dawned on me that it would be incredibly easy to hijack someone's identity in the blogsphere. How do we know that the comment left by "Seth Godin" actually comes from the famous author and not some mischievous troll? I doubt there is much money in it but it certainly could be used as a vehicle to ruin someone's reputation and as far as I can tell there is nothing stopping someone other than myself from commenting elsewhere under my name and linking back to this blog.

As a we all build out our blogs, personal websites, MySpace, LinkedIn, etc., web presence becomes increasingly important to our reputations. Whether its researching someone prior to a meeting or applying for a job, the importance of personal web presence seems to be growing rapidly and this could become a major problem.