The Spanish air traffic controller was real it has been confirmed by the industry he existed and was a controller in Kiev. He has since disappeared and his twitter account has too. His tweets were copied before the account was taken down.
People are saying because the account was taken down and he has disappeared than it was faked. Now does that really make sense? No.
This site is one I highly recommend people going to for eyewitness accounts and what they saw in the sky and on the ground immediately. It differs from the U.S. and Ukraine version of what they want out in the world. The eyewitness accounts confirm fighter jets with MH17 and confirms everything Carlos tweeted. The site above has a lot of articles, just scroll down.