Inform user about unnecessary background data
I used boxer on cyanogen mod and synced my calendar for testing with a webdav-server. The service is now no longer available and here is my problem. I have no mails in the configured account and about 15 appointment items to sync and the app used 1,26GB of my data volume on only one day. I disabled background data for this app to fix this problem.
Maybe u can count the failed request trys and inform the user if an irregular amount occurs.