Zemanta is a content discovery platform, they have a popular WordPress plugin that helps bloggers find related posts and related images while you write your post.
It does mention a bit on links on the plugin page:
Link Love by linking to other bloggers' related posts. In turn, we'll recommend your posts to other bloggers. Then find out how much love (links, tweets, likes) your posts received via Zemanta Dashboard.
So the links are not automatically added, they are suggested to the bloggers and the bloggers can add it. Is that an issue? Probably not.
What might be an issue, as WebmasterWorld martinibuster said in a WebmasterWorld thread, the links to Zemanta's web site.
Chris Boggs noted in a Facebook post, which is private, but martinibuster cited it in a public thread, that a Forbes article has links to Zemanta's web site for the keyword anchor text of "SEO" and "PageRank." How is Zemanta related to those keywords he asks.
I thought it was all good until Chris Boggs, in a Facebook post, noted the dofollow links to Zemanta embedded within a Forbes article, using the anchor text, "SEO" in one place and the phrase "PageRank" in another spot within the article. Really? Zemanta feels it is relevant for the phrase, "PageRank?"
Is this going to get Zemanta in hot water with Google?
Forum discussion at WebmasterWorld.