[333c]

Too much effort. Just print out a picture of a person with open eyes.

At that point it's really just the honor code that holds us to honesty.

[jpalomaki]

Add heartbeat detection to verify the person is alive. [1] has one example, Google "use webcam to detect heartbeat" to find more.

[1] https://github.com/thearn/webcam-pulse-detector

[adrianN]

Add gaze tracking and have people look at a randomly moving dot.

[quickthrower2]

While entering captcha codes every 10 seconds

[byronhsu1230]

This is so useful!

[dole]

Measurement of other minute facial feature movements besides blinking to detect whether it's a real person vs picture or other video?

[Wowfunhappy]

I think we've just discovered the real use for Apple's Face ID. Staring contest video games.