I have an S3 and I always have this option enabled. Whenever I accidentally tap the screen to turn background data back on, I immediately go into settings and disable it again. But today I can't. I go to Settings-Data Usage but I no longer get the option to disable background data. All I get now is Auto sync data, mobile hotspots and show units. It was there 2 days ago when I accidentally enabled it. I'm running 4.2.2. How can I disable background data now?