You might not be fully and 100% aware of everyone you are linking to. You could even be linking to a bad-neighborhood site without realizing it. There are a few ways this can happen.
Lately there seem to be quite a few bloggers using contests to get more traffic to their blogs. Smart idea, if your blog is already big enough and/or you have some resources or connections. One example is this post here at John Cow, http://www.johncow.com/win-big-time-with-storestacker/. It’s like a virtual raffle where you earn more raffle tickets by tweating and linking and posting for the blog that is running the contest. John Cow is offering some pretty heavy prizes, of both the hardware and software varieties. One of these is what looks like an incredible tool for affiliate sites – Store Stacker. And Mr. Cow has also recently posted some instructions and tips for starting your own Blog Contest. You can see this at http://www.johncow.com/planning-a-contest-to-get-the-buzz-going-part-4-of-anaudlife-dot-com/. Not everyone is in a position to offer prizes like our friend Mr. Cow. But .. who knows! Maybe you have your own eBook, or some friends in the right places somewhere who could help you offer some prizes. Could be a great way to get some more attention for your blog!