If you're countryX and want to bring down everything, hacking sites like mysql, apache, kernel and the likes would do the most damage
'Usual' hackers are probably a step above script kiddies. On the top end you have state sponsored PHDs
It's an internet forum, not a court of law. OK? I am speculating. When someone does something this big, I tend to think of someone way out there, like those that tried to hack Google, defense companies etc. For all we know they did to get the info from one company, steal CC from a million of them, or just have the option to take million of sites offline. Relax.