So does it mean most alien invasion movies are wrong when they try to suck water out the ocean for energy? Like in Oblivion? What they could have done is to sta

So does it mean most alien invasion movies are wrong when they try to suck water out the ocean for energy? Like in Oblivion? What they could have done is to stay inside the Earth forever (like in War of the Worlds at least) and extract water from there instead.