[subway]

Say what?

All those legacy systems (probably) shipped with a weak IR filter, but the CCD on the the devices will more than happily react to a bright IR light.

This is even how the majority of "night" cameras operate. They ditch the IR filter, then illuminate the scene with IR.

[lakechfoma]

Yeah this is what I was getting at. How many old cheapo security cameras have no or bad IR filters if that was still the standard for ~2012 flagship Android devices...