Theory put out there by SearchEngineland's Barry Schwartz based on some tests published by Dan Petrovic (nothing like a kindergarten he said, she said, 2 x test theory right? ).

Hijacking Google Search Results With Duplicate Content

I always wonder if Google creates more second and third order negatives than they realize with each new algorithm "animal" myself....

Kind of like battling crime...do you hire more cops, create more rules, or spend more money on addressing the root causes of the perceived "bad behavior"....I almost think you need to keep the rules in place, then just attack bad behavior (in your eyes) directly, vice doing the super-secret algo changes that are similar to WW 2 carpet bombing...yeah you kill some bad guys, but you take a lot of good ones down too!

Anyway, thoughts are welcome.