It’s not often that wildfires spread from other parts of the blogosphere into the main Linuxy downtown, protected as it is by all the surrounding free and open lands. In the past week or so, however, that protection wasn’t enough. A fire broke out on AlterNet the Thursday before last — that’s part of the blogosphere’s progressive territories, just east of Huffington — and within a day it was blazing out of control here in the land of Linux as well. The cause of the conflagration? An undercover expose of Digg that’s enough to make even the cheeriest Facebook fan swear off social media altogether.