If you ask Glenn Greenwald, nothing at all (my emphasis):
“What makes the Anthony Weiner story somewhat unique and thus worth discussing for a moment is that, as Hendrik Hertzberg points out, the pretense of substantive relevance (which, lame though it was in prior scandals, was at least maintained) has been more or less brazenly dispensed with here. This isn't a case of illegal sex activity or gross hypocrisy (i.e., David Vitter, Larry Craig, Mark Foley (who built their careers on Family Values) or Eliot Spitzer (who viciously prosecuted trivial prostitution cases)). There's no lying under oath (Clinton) or allegedly illegal payments (Ensign, Edwards). From what is known, none of the women claim harassment and Weiner didn't even have actual sex with any of them. This is just pure mucking around in the private, consensual, unquestionably legal private sexual affairs of someone for partisan gain, voyeuristic fun and the soothing fulfillment of judgmental condemnation.”Let’s stipulate that, as matter of morality or law, no one besides Weiner’s wife has been injured by his Internet adventures. That doesn’t change the fact that Weiner aspired to be, and until a week ago had a pretty good chance of being, the next mayor of New York City. I don’t think I’m succumbing to a New Yorker's chauvinism when I say that, other than the presidency, that’s about as challenging an executive position as there is in this country, arguably more important to the life of the nation as a whole than all but a few governorships. Does Greenwald really believe that the Weiner’s display of juvenile recklessness and his readiness to lie through his teeth is irrelevant to his worthiness for that office?
The people finding a little diversion in Weiner's travails aren't the only ones luxuriating in the “soothing fulfillment of judgmental condemnation”?