And if these cameras were turned on (and they're not). Where the heck would they store this literal terabytes and terabytes of data? It's not like there a little Ethernet cable that the planes plug into to upload data every flight. And in flight wifi? Good luck with that satallite connection. Airlines are not in the spying business. Nor is Panasonic (the makers of this particular type of IFE).

Frankly, airlines don't even want these systems on their planes in the first place. They weigh a lot (more fuel for the airline). They can break. If it does break customers get pissed. It's another cost for them. The only reason they're on planes is because customers want them. A lot of airlines are moving to BYOD systems on shorter-medium aircraft to remove the IFE screens entirely.

Yes there are cameras onboard. But there are literally no incentives for the airline to capture this data. Frankly, I'd be more worried about the thousands of airport cameras you walk by just on the way to the plane. The airport is government property. The government has an incentive to track certain people. Airlines couldn't give a literally flying shit.