I'd wager that they can suck up more than just visible light with that system.  At the very least they'd be fools to not collect cellular transmissions so that when they download the data at the end of the day they can tell who the people are based on their personal tracking device.  Most cameras can also pick up the infrared spectrum as well which would be invaluable with a system like that. If you really want to be freaked out though just know they only reveal such technologies when they're already two generations beyond it.