CSS Visual Cryptography
Daniel Erenrich

You can make out motion in the encrypted video. I think it would be more effective to leverage this technique to overlay two youtube videos that both appear to be random static that changes every frame, but the video becomes visible when they are combined.

That approach may suffer due to compression algorithms, though.

One clap, two clap, three clap, forty?

By clapping more or less, you can signal to us which stories really stand out.