I have done long haul 2.4ghz wireless links before with directional antennas (60+ miles).

36K feet is 6NM vertical. I have an antenna in my car, and enough power with the car running to reach a large aircraft audience. This doesn't even take into account if I have the transmitter and a lithium ion battery in my luggage (I've travelled across the world with Pelican cases loaded with AV and IT kit; no one asks, and they've only been opened by the TSA twice).

TL;DR Unauthenticated, unencrypted radio protocols are vulnerable, that's all.