I think the problem isn't the search engine, the problem is that the advertisement is allows on such sites. It generates value for noone, especially the adverts firm. How about the net-ads get a hold of themselves and stop accepting any webpage as a potential ad-spot. If there were a policy that said that ads would not be put up on sites that scraped content of other sites just to get webhits, then this problem wouldn't occur. Infact, ads would become more valuable so such a policy could be a win-win.