Security researcher Dancho Danchev said Friday that <A HREF="http://blogs.zdnet.com/security/?p=986&tag=nl.e550">SEO poisoning attacks have scaled up</A> and are attacking well known sites. Google has been filtering its results as a defense, but Danchev's latest finding brings up an interesting question: Can the defenses scale? First, a few key points. SEO poisoning isn't new. In fact, targeted IFRAME attacks have been around for months.