Picked up this call on my cell phone b/c I was waiting to hear from a desperately sick relative. When I told the caller I was on the DNC list, he hung up! I don't know why this particular scammer irritated me so much, but I called back, and said I was posting a notice on 800 Notes about their duct-cleaning scam...and, of course, he hung up again. I think my next action will be to schedule a service call at a fake address--maybe several of them--and waste their time as much as they're wasting other people's time by making unsolicited calls. I usually just ignore these things, but I missed the first call from my relative b/c of this jerk and feel like being really vindictive, just for a change of pace.