If we could make it work (and I recognise the problems other commenters have noted with this particular implementation) then this would be a big benefit for bl

If we could make it work (and I recognise the problems other commenters have noted with this particular implementation) then this would be a big benefit for blind people, for whom CAPTCHAs aren't just inconvenient but impossible. I'm sure they would gladly accept 8 seconds of unresponsiveness while the computer did some verifiable work, if it meant they could pass the test and use the service.