> we have the same problem with hundreds of porn splogs linking to us.
> Google do seem pretty efficient at ignoring them so their impact on
> our serps is barely noticeable in Google. I think the motive behind
> them is either to generate adsense revenue from scraped content and/or
> a competitor or plagarist using them to  copy the contents of your
> pages - which although Google will not initially index (because its
> duplicate content alogs filter them out)  there will be a day when for
> example your server goes down or a coding mistake is made on your
> page, which enables the plagarists copied content to get indexed in
> priority to yours.