That is exactly what a Botnet based DDoS attack represents in the networking world. Coercion replaces loyalty as Malware perpetrates through the network to increase the size of a herd. All you need is the right triggers (like people who will click through links) and crowd-sourcing takes over. Last year Craig Labovitz at Arbor described a DDoS at over 30Gbps on an Asian mobile operator. It is likely to have been done with a herd numbering in 10s of thousands rather than the order of million botnets known to exist today.
This is a new turn to what was ‘affectionately’ called the Slashdot Effect in earlier days but, with a bad twist. Traffic is intentionally diverted by a botnet herder. Their target might be popular but does not really appreciate (nor can benefit from) the incoming volume.
First thing to note about a DDoS (or DoS in general) is the fact that trying to throttle such an attack is actually playing in the hands of the attacker — a self-inflicted denial-of-service. Trying a selective block is not very fruitful when the attack is distributed well over the Internet landscape and, laden with guerrilla tactics.
It is more of a pipe-dream to expect everyone will protect their end-hosts from
Malware attempts to subvert and assimilate into a growing botnet. And waiting for a curseder (good-guy) that will spread along the malware channels to wipe out the bad-boys has its own risks.
At a higher level, the Internet infrastructure could analyze elements of such a botnet and attempt to sterilize it (a quick and more generally visible example is OpenDNS).
If a potential target (company, nation; Google?) can afford distributed hosting on the Internet, it would make an intimidating challenge to the botnet with multiple points that need to be compromised before a successful DDoS is achieved. This is when a larger Botnet will have to rear its head for a Multiple DDoS.
As malware writers get more sophisticated, the attack itself is more silent and versatile. But, DDoS is not a one-way tool and can be used by both sides. Around the start of this month, Aiplex Software was hired by the likes of MPAA and RIAA to attack piracy sites. This instigated a retaliation which is currently in progress (www.aiplex.com is off-line as of this writing). So, which side wins with this? None, I guess if anyone benefits, it would be the RBN, and ultimately terrorist organizations, probably.
But, this is not yet the end of this story and over time I expect we will hear more on this round of DDoS.
Meanwhile, you can catch the background on this from a recent non-fiction book Fatal System Error – The Hunt for the New Crime Lords Who are Bringing Down the Internet, by Joseph Menn. It runs though an account of such warfare over the last decade taking specific examples (see Prolexic).