Fascinating stuff, not at all what I was expecting. Two things come to mind reading this.
1.) The crowdsourced and algorithmic solutions seem to be framed in contrast if not exclusive to each other here. I wonder if combining the two couldn't have helped avoid this:
>'However, the crowd was hopeless against a determined attacker. Before the first attack, our progress on the fourth puzzle had combined 39,299 moves by 342 users over more than 38 hours. Destroying all this progress required just 416 moves by one attacker in about an hour.'
I'm wondering if it's easier to create a 'bouncer' algorithm that detects and blocks/reverts aberrant behavior than to solve the core puzzle itself. If that problem is in fact easier - identifying 'hurtful' or unusual moves, could addressing it help the core solution by helping avoid non-malicious 'back sliding' too?
(I have no clue about these things.)
2.) The sort self-importance expressed by the attacker is just awful.
Unlike the author, I don't see it as a concern about "how crowdsourcing puts the collective potential of humans above technology". That almost sounds noble.
This impresses me as plain old envy and entitlement, an overgrown cousin to every "Why is this on HN?" or "Why is this on the front page? I submitted this before and no one voted for it." comment on HN. The whole thing is one big "should" of personal gratification.