DDoS attacks aren't aren't technical problems - they're political ones. Political problems need political solutions. Technology isn't the cause of a DDoS attack, just the medium.
That seems like telling someone to eat more healthily when he's presenting with a heart attack. And like heart attacks, not all DDoS attacks have logical causes that can be mitigated against.
They're both. Even with willing ISPs and countries on all sides, the attacks continue.
Machines are far to insecure, which makes it far too easy for an individual or small group to harvest the resources of millions of machines and then hide, while giving them orders.
It's when they try to collect money that law enforcement has the best opportunity to catch them. There is a monetary limit over which it becomes internationally interesting to the FBI,HTCU, etc, to get involved and start using international resources to track the money back and make arrests.
Yes it has. Unfortunately I can't really say much about the parties involved or what happened (I wasn't the bad guy though, promise), but it absolutely has, and if I've seen it, then either I'm a unique little snowflake (yay!), or it's happened a LOT more.
I assume that this is pretty common situation in some (even non-criminal) circles, I'm thinking of various small web hosts, content-free portal pages, direct internet resellers of something etc. Few times some of these people actually went to us seeking help with something almost clearly unethical and possibly illegal. This is in Czech republic, but from various stories on internet I extrapolate that this is probably global phenomena, maybe even more pronounced in other countries.