Re: BT already doing somtehing

Very much so. BT gives you 24 hours to fix your PC or you're "cut off" until you confirm the machine is fixed. They provide a modicum of help, pretty much restricted to a few online av scans, but after that you're on your own.

And yes, the abuse team does look into zombie/dDos activity too. I believe they rely on third-party reports, primarily, but I do know that they have people specifically dealing with security issues other than spam-generation.