The engineers who designed the Predator were not idiots, adopting Security through Obscurity. The feeds were not encrypted for at least two reasons: The Predator is supposed to be able to go at a moment's notice, and having to wait around to be keyed for the mission at hand as required by NSA, defeats the purpose. I've heard the expression "80% of my intelligence needs that I can have NOW, can share it with coalitions, and don't need a security officer and a safe to transport it around the battlefield is a dream come true..." In any case, the imagery doesn't tell anyone anything they don't already know, and has a quick "half-life" meaning it rapidly becomes irrelevant. It's just not worth encrypting. Not saying that we don't do stupid things, just that not encrypting the feed was not one of them.

Why not develop something HTTP based, so you would be able to access it from any paltform with a browser?