code15: This may be completely naive..
But if a "handful" of customers with malware are taking down sparks entire internet service, why don't they just kick these customers off the network until they are able to contact them and remove the malware?
I would say this has a better than even chance of being rubbish.
It may be true to a lessor extent, so they're not lying, but usually Spark IT is not really up with the play.