People being hacked since the last Server Check.

Going by that, I would assume that this sort of method would not be very widespread, as it would require a fair amount of technical knowledge to operate. Furthermore, like you said, it would be difficult to target a specific account, and far easier to simply hit random ones.

Since most of the account hackings (or at least the ones we hear about) seem to target big fish, I'd say this packet method isn't the main way people are being hacked.

The fact that it hits random accounts make me think this is the method and most of the account hackings we hear about are not from rich people o.o.

Well .

Getting banned/trouble logging in?/ID already logged in seems to be the only way to avoid that I think... that's really scary.

Yeah, probably. I know a few people who never log off and they are still safe (for now), but other mules were already hacked.