I agree. I seem to remember Arrington posting rumors about last.fm handing user data over to the RIAA back in February, and then AGAIN in May. As far as I know, both of these rumors turned out to be false. He never said anything about his source, just that it was a very trustworthy one, and he never posted a retraction. He did, however, make a post in May ridiculing last.fm because its servers overheated and were taken offline.

Here's an article with some actual fact checking: http://www.guardian.co.uk/technology/2009/may/28/not-safe-for-work-last-fm (sfw). I didn't like the fact that comments on TechCrunch that offered any opposing viewpoints were promptly deleted.