Hacked sites are a dominant strategy is many markets right now. Perp will Hack N sites, cloak them so only the googlebot sees the hacks, and use those links to drive rankings of a site in a highly liquid market place (Pharma, gambling, payday, insurance).<p>When google can't devalue hacked/cloaked links well, I expect much collateral damage with Penguin (since it has primarily been focused on low value links). It won't be a precision attack on webspam.