This is genius.

My parents house in the UK receives about 8-14 of these calls every day. I've been dreaming about creating an asterisk-pbx-powered spam call catcher for them.

I'm now thinking about it more seriously…

Indeed genius. Google ought to implement this in Google Voice for all their unassigned numbers. Any Googlers up for doing it as a 20% time project?

Awesome. And it only goes to show that the goons they hire to man these lines are getting minimum wage for a reason.