tedster - 5:52 am on Mar 13, 2011 (gmt 0)
Speaking at SMX this past week, Matt Cutts confirmed a good bit of what this thread is saying. Vanessa Fox reports:
Matt reiterated that competitors generally can't do anything to hurt another site. The algorithms are built to simply not value links that violate search engine guidelines. Demotions generally only occur when a larger pattern of violations is found.