wtf Google's "suggested groups" for me?

[arethinn]

Ebay - join
Group description: Ebay auctions and more
237 members

okay, I suppose. I am not sure exactly what search data it distilled this suggestion from, but it's not that weird.

soc.bi - join
Group description: Discussions of bisexuality.
Usenet, public

again, not sure what precisely this would have been based on from my aggregate data. probably not anything particular but just "other people who who also searched for that searched for this as well" kind of thing (although they have missed the mark in suggesting it for me).

alt.lifestyle.master-slave.personal-ads - join
Group description: Master/slave ads.
Usenet, public

but....

I give up on this one.