Linking to Sites Selling Academic Products

How harmless (or harmful) is that?

[languageusa]

What about linking to sites that are selling (custom made) term papers, college essays, research papers, dissertations, etc. Will I be in any way
penalized if I link to such a site? They obviously support academic fraud, which does not go well with Google's philosophy -- or am I wrong? Thanks for your help.

[ganderla]

When I first launched an educational site, I traded links with one of those sites and I saw no adverse reaction. I eventually took down the link and I had a few visitor complaint. I now in no way need that site linking to me.