I disagree. Mobbing existed before anonymity; in fact, it was very much the norm -- the concept of "honor" is often tied to public displays of condemnation for the "dishonorable". Publicity makes it harder for people to disagree with what is perceived as the opinion of the majority, as unpalatable and uncivilized as it might be. This is why political votes are secret, among others; or why the Gospels explicitly warn against public displays of faith.

Every group of people will have its "dishonorable" enemies, and will always be keen to publicly shame them. Forcing people to attach their public identities to online activity will do nothing to dissuade people who see such actions as a badge of honor, but it will chill the display of dissent from the status quo.