This was the exception proving the rule. Digg is not the leading social site it was a few years ago, so it's just been used to provide G with its "Sista Soulja" moment. Google has recently slapped two selected high profile sites (BBC, Digg) that they could afford to slap, to put out evidence that, yes, they could punish the big boys. Now they'll go back to their normal mode of protecting big Inc sites while slapping all the small IMers. If anybody complains about the favoritism, G will hold out the Digg example for the next decade, to show they they can too punish the large sites.