An interesting tidbit on Techcrunch: Yahoo's $100m acquisition of Rivals.com may be in doubt, because the sports site's CEO was involved in a pump-and-dump stock manipulation scheme in the 1990s. A deal to sell the site to News Corporation's Fox Interactive died after a routine background check revealed the prosecution. I'm guessing that Michael Arrington's source is Ross Levinsohn, former boss of Fox Interactive, a friend of the tech news site. [Update: Levinsohn emails: "100% guarantee you that the rivals thing isn't from me. I happen to like them very much as a business."]