Re: planet is surrounded by spy satellites
Do you know how big the planet is?
And do you know how small the resolution required to see a plane is?
Hint: No, you can't see the Great Wall of China from space.
Sure, if you want to peak at a building in the Middle East, you can move the sat to look at it and take hi-res pictures, etc. But over 25,000km of empty ocean, not a chance that you'll see more than a dot, and that'll be hours stale, so you'll still have no idea where it went or what happened or even what direction is was actually flying in by the time you get the image back.
People forget that, tiny though the planet is, the world is HUGE and there are all kinds of humongous things that just aren't visible unless you're specifically looking for them, and that even when you're looking for them aren't easy to track - because we HAVEN'T turned thousands of miles of empty ocean into 1984-style surveilled territory for one-in-a-million plane flight that we had no idea was going awry until it was far too late anyway.
Seriously, go find a whale on Google Earth. I guarantee you that in the vast trackless ocean mapping there, there's a whale surfacing somewhere, because there are hundreds of thousands of the damn things and they're huge. Don't cheat. Start in the middle of the ocean, max-zoom, and go find one, just by looking and scrolling around.
Now guess what? Google Earth is updated once-in-a-blue-moon for most locations like that, and even if you saw the whale, could you tell where that whale was now? Absolutely not. That's pretty much the best spy-satellite you'll ever get to play with, and it's damn useless for that kind of task.
An MH370 plane has precisely 60.9m wingspan. Let's call that 60m. Let's pretend it's square and obvious, to make the maths easy, so call it a 60m x 60m sheet of metal. That's 3,600 square metres. The search area is 25,000 square kilometres. Which is 2.5 x 10^10 square metres. That means you could fit, in the search area alone, 6,944,444 planes. 7 million planes. You'd have to search 7 million plane-sized images to find it. If each image took 1 second to photograph and transmit, it would take 84 DAYS before the amazing-mega-spy-sat-2000 went back and took the next image at the first spot. If the plane WAS in the search area, and you stabbed at a point at random, you stand more chance of being struck by lightning than hitting the plane. And that's if it's fully visible and not submerged, broken up, confused with anything else (e.g. whales!), etc. AND that it's in the area you're looking at.
Add in the 3D of water and ocean and junk settling on something on the ocean floor and you stand slim chance of finding it even if you have a rough idea where it went down.
Despite what the movies might show you, satellites aren't that good (limited by the same stuff as telescopes on Earth spotting those satellites), nobody sits watching thousands of miles of empty ocean, and a plane going down is a tiny speck in the world.