Started using TOO much data with iPhone 4. Was using less then 200mg a month now using over 500 ...?

Did you update or install Facebook recently? Or change Facebook options? It is a real data hog.

I don't have the app, so I can't really answer. But if you have it set to keep local copies of content (particularly images) it can add up. Another user just freed up 5 GB from the "Other" category by deleting the app. And all of that data had to come in to the phone, either over WiFi or cellular.

I have experienced the same exact problem this past month, triple what I use and have done nothing differently. I do have Facebook, but I have had it for months and did not update it. I would like to know how to resolve this, I'm afraid to use any data right now.

I am having this same issue. There has to be a way to go into the settings or some other menu and figure out how much data each app is using? I called Verizon, they said some apps run "widgets" in the background that can use a lot of data, but she couldn't figure out how to check this and told me I should contact apple - any one have any ideas????

I looked around for more answers, found that people were having issues with iCloud updating during the middle of the night using the cellular 3g not wifi. I've turned off my cellular at home so it will only use wifi, and turn it back on only when I need it. I've also turned off the backup in icloud and will see how that goes. I also was told by an ATT&T support person to download an app called Onavo Count that will keep track of which apps are using the most data. Hope this helps.