I maintain that the real issue here was not the um, "activity", nor even the cover up, it's the weird self-destructive yet attention seeking behavior of Weiner throughout these last few weeks. He could have dealt with this in so many better ways. The fact that he didn't makes me think there's more here than we (yet) know.
And maybe it's what Reasor says, these messages were not solicited. (Of course, those poor girls are going to say that now: maybe in the event they were more receptive).
Fact is, you look at those pics and messages and the guy comes off as just fucking weird. And then when confronted with what he's doing, he gets really weird, before going all out weird and checking himself in for compulsive Tweeting or some such. Weird. And Pathetic. That last is what sealed his fate.