would you wait instead of entering captcha with hashcash.io widget? Widget like that - https://hashcash.io/auth (notice unlock switch)
absolutely not -- at least not on every login into a service.
the on/off metaphor is not clear either - at least make the "login" button be not enabled until the switch is moved
Its sitting on the login form for at least a minute now, filling up the switch background btw
It was for a contact form on a vendor's website. Ended up going with another vendor who had identical product