"It may surprise you to hear it is no more acceptable for a member of a group to tell a joke about the group than it is for a non-member. No matter who is telling the joke, the behavior contributes to an atmosphere of disrespect and discomfort."

It looks to me as if the word "group" is being used in two senses in that sentence. If it just means within a mixed group at work, fair enough - but if it means that a bunch of Black, or Jewish, or Catholic, or Irish etc, friends aren't entitled to joke among themselves, and about themselves, that's a step too far. And when you take a step too far you fall over the edge.

And Mmario is right on about the way in which stereotype joking and sneering at men on the part of many women can seem to escape the kind of self-scrutiny and challenge that is mentioned in the article. ("Having a bad day Mary" is just the kind of put-down some men are only to make to a woman who raises those kinds of issues.)

(Incidentally what's with "Sondra Thiederman PhD" ? Surely people haven't taken to putting their degrees down on their posts?)