I recently noticed that my android phone was incurring data charges (while I was not on data plan). Initially, I thought it might be due to a virus, rogue app or some setting I may have accidentally activated.
In order to trace the issue, I started removing apps from my phone, but the data charges kept happening. On the first day the charge was RM5 but subsequently it ranged between 2 cents to 20 cents. In order to stop the hemorrhage, I activate a one month plan. The one month plan was RM 30 for 30 days, but the unknown data usage had already cost me RM 15 without any benefit to me.
I also tried resetting the phone to factory mode, but found that the phone automatically restored some of the applications that were still installed - great feature, but not when I am troubleshooting this data leech on my phone. Resetting the phone helped in resetting the data counter and allowed me to see the amount of data consumed. It was the background data were incurring the cost of my mobile data. The foreground data was primarily from wifi.
Other things I tried was to restrict all background data. The bleeding continued, but I noticed that all the data consumed by the system. At the end, I finally concluded that Google Now was the data leech.
I was unable to confirm my finding earlier (because of the mobile data subscription) but its been one week since my data subscription ended and I have not seen any strange mobile data usage.
My primary concern is that the phone was still incurring mobile data usage even though the mobile data was turned off. Good thing I was not travelling. If I were, then I may incur roaming data cost as well.
I am surprised that Google Now does not respect our setting of keeping the mobile data off. So for now, I will do without Google Now. It was fun to use, but should respect our settings.