In addition to what I wrote above, I have found another major problem which I did not realize until just now. After the iOS 6 update, my phone now disables WiFi when I put it in sleep mode. That is likely why my data usage has skyrocketed. If I start a download with WiFi on, put it in sleep mode as I always have for it to download while I listen to something else, it switches so that it eats up my data. Same thing about streaming stuff or whatever else. Ugh, this just gets worse and worse.