Referer Spam

I believe I have been receiving a new kind of spam, at least for me this is new: My Own Perl Webstats for Yashimas Homepage show some pages among the referers that are surely porn sites that do not link to me:

Those are only 12 hits and might be that in the middle of porn-surfing someone clicked on my page but since those are very simliar I guess that it is spam.

At the same time the stats tell me that there are more and more normal sites that have a link somewhere to my page. I am not yet worried about traffic though as it only amounts to about 100MB per week so far.