Is it possible to tell Yahoo which sites you would like your paid search results to appear?

I have found recently that I am receiving a lot of clicks from their little known 'search partner' sites. The main culprits seem to be the one page search box sites where you enter your search phrase and it then all that appears is a list of the Yahoo paid search results.

I have never heard of most of these sites and am curious where they are getting their traffic from, if indeed it is legitimate traffic and not down to click fraud.

It would be useful if you could tell Yahoo that you wanted your results to only appear on certain sites eg Yahoo, AOL, etc. or send them a list of the sites you did not want to appear on. Anyone know if this can be done?