Hackers, quite possibly from the government, replaced Anonymous DDOS software available for download with a version that steals passwords.
What we’re learning here is that there’s a serious flaw in how Anonymous works. By being so amorphous and disparate, there is no control over the members of the group. Incidents like this can easily happen because there’s nobody watching the hen house.
This telling example demonstrates one of the oldest splits on the left, that of centralized authority (Marxist) vs decentralized groups (anarchist.) The Marxist approach can lead to rigidity and calcification, while the anarchist approach can mean no one is really in charge. While Anonymous is more libertarian than left or right, this certainly applies to them and their anarchist organization style.