Web hosts are typically in a very powerful position. One such example is discussed at a Search Engine Watch Forums thread showing how one Webmaster was finding "strange results" in the Google search results pages. The results contained pornographic terms in the description area of the search results for that listing.
Matt Cutts from Google explains that this is not any form of 302 hijacking but rather a rude cloaking bot implemented by the web host.
To me, it looks like this webhost is cloaking. Then including links to porn on the cloaked page that is served to Googlebot. Neonblitz, this is just me speaking my personal opinion. My personal opinion is that if you find out your webhost is cloaking, monkeying with your content, and adding porn links to your page, you'll want to think about whether that webhost is treating you with the respect you deserve.
So be careful with whom you host with. This can hurt you big time, both in rankings and in search results branding. How can you tell if this is happening to you? Well, I guess you can try the site command search (i.e. site:www.domain.com search in Google) and look through all the listings. Or even conduct a site command with a porn phrase such as [site:www.mydomainc.com porn] or [site:www.mydomainc.com sex] and see what comes up.
Forum discussion at Search Engine Watch Forums.