It isn't, naturally — it's more likely just that the paper naively picked up a revenge story from businessman Murry Gunty. See, Pincus blogged about his classmate Gunty this January, recounting some old college ethical scandal and citing Gunty as an example of an unpunished bad businessman. Gunty wasn't happy, so he called Six Apart — the people who host Pincus's blog — to tell Pincus to take down his article or remove Gunty's name.
Pincus, liberal First-Amendment-Rights-believing hippie that he is, said no. Six Apart's execs checked out the situation, decided Pincus was right, and stopped bothering him. A few weeks later, the Washington Post turned it into a story of how bloggers can wreak havoc on someone's reputation.
The Post says Gunty declined to be interviewed for its new story, but Pincus accuses Gunty of hiring a PR firm to get this story published. Geez, if Gunty did that, he really got screwed, since the Post calls him out for censorship and raises the whole unsavory issue to the public again.
So Pincus is acting like a paranoiac, and even his blog commenters are arguing that the Post piece was really pro-Pincus. Looks like you can't rile up a mob like you used to.
This is a stupid move for Pincus. First off, he could have passed this off as a positive article just by picking different excerpts. Chalk that one up to his lack of slick PR ability. Second, this is especially bad timing since he's recently re-entered the public eye by returning as Tribe's CEO just a few weeks ago. He's exposing the tired "old vs. new" trick, which bloggers don't buy any more, and that can't help his popularity among the insular crowd at Tribe (where many members know and love Mark).
In any case, Mark shows the responsiveness that makes Tribe users love him, posting a comment on his own post acknowledging other commenters' points. Chances are this is just a hiccup for a happy hippie.