Is This a Hack?

I've had this happen to me several times in some games. When i come close to some champs my keys lock and I cant cast spells or buy items. The arrows that show up in blue when you click somewhere to move, turn red. I can move around and I can alt tab out. I tried hitting the A key, but it does nothing. I've also tried the drag mini map thing, did nothing. I'm suspecting that there's a hack some players have. This usually happens when I start winning. Any clues? here's a screen shot of the red arrows that I was talking about, I took it while i was spawning but it's the same once I do.