That hacker is claiming to be attacking Facebook and bringing it down using a CSRF attack. Sounds like crap to me, it was probably just a problem with DNS or something.
I agree. This was a damn good way of handling the situation: taking care of it head-on instead of watching from the sidelines and hoping things get better. I didn't think they would do much (except for maybe a blog post about how you shouldn't give your password to anyone or something similar), but this is totally beyond what I expected.
You are confusing DRM for the locking down of a product or platform. Apple locks down iOS for the benefit of the user (most of the time), but adds DRM to apps to prevent unauthorized code from being executed on the device and to prevent apps from being pirated (which Installous has proved futile).