I've had auctions pulled because I included onthedash. From what the ebay people have told me, they do random checks and if they find a website link, they will pull it. More often, however, some reports the auction and that's how it comes onto their radar. Usually, it's a competitor who makes the complaint, but as long as it violates the rules, they have to pull it.
What I find most disturbing about it is that they just don't delete the offending material or link, or give you a heads up to delete it, but pull the whole auction. I can understand when they pull a scam auction, but for legit auctions it seems like overkill to pull it because of a minor infraction.
Scott