I got SOOOO lucky last night. I was playing and my hyperwave decoder picked up a small UFO, manned by ethereals, my first this game. So I shot it down, and got in close...and then the b@stards mind started mind controlling. However, I only lost one guy, and I recovered a LIVE ethereal leader!!!
I've already got Psi Labs and Mind Sheilds going up, and I'm researching the Psi Amp now. And have yet to go up against any more ethereals yet. Perhaps by the time I encounter them again, I'll have SOME sort of protection.
Also, I HEART shooting Mutons. Filthy animals.