I call BS on the whole DDoS thing. And it especially wasn't those Phantom kiddies. No announcement before the downtime, and then, a while after people notice that Steam is offline, "oh yeah, by the way, that was us, like, totally!" …yes, sure. Also, the way in which all geographical regions went down almost simultaneously, heavily suggests an internal issue, and not an attack. Of course 1000 scriptkiddie groups will try to claim responsibility, but most likely it was nothing of the sorts.

Still, I think it's good that people occasionally get reminded about what it really means for them if they "buy" games from a service with a dependency on remote servers.

Speaking of which, from being forced to try the whole Steam Offline Mode thing several times due to local Internet outages, I feel confident in saying that it's very likely to not work when you would need it to. In my case, Steam would usually just try to connect for hours, not even giving me the option to choose offline mode. Or it might offer offline mode, and upon choosing it immediately fall back to the "retry or go offline" dialogue, ad infinitum. Or in the few cases that it might agree to start in offline mode, many single-player games still won't run because they implemented their own online dependency (some just due to being poorly written, such as crashing if they can't access Steam for achievements).

It's hit and miss, to say the least. And quite frankly, for software that I'm paying for, that's simply unacceptable. There should not be an external entity telling people when and how they can use the software they bought, whether it's deliberately or by accident. Online DRM is a defective design, there's no two ways of looking at it.