Motorola Atrix 4G :: Extremely Large Data Transfers By Motoblur?

Ever since the wi-fi at my work stopped working (whole separate issue which I still haven't figured out), I noticed my cellular data usage spike up significantly. Now obviously this shouldn't be surprising, as I've had to use cellular data instead of wi-fi, duh. However, all I really used my phone for at work was to check email, and the attachments were set to never automatically downloaded. I started analyzing my AT&T bill and noticed random large chunks of cellular data usage: 3-4 mb during the middle of the night, 15mb during the day, etc. The other day, my phone transferred nearly 40mb for 3 hours straight! I called up AT&T tech support, and they eventually put me all the way to Motorola second tier support, and yet no one could tell me what was going on. All they could tell me was that Android phones normally transfer data here and there in order to sync. BS -- the only account I have on sync is my gmail email and work calender. I have ZERO social applications set up with Motoblur.

After 3 hours on tech support, I gave up and decided to start toggling some settings. I turned on "Sync over Wi-Fi only" for data delivery of social applications, and this seems to have fixed it. The past two days my AT&T usage logs only show a few KB here and there. My battery also seems to last longer now, as it's not being forced to transfer data over 3G/4G for hours on end! Since I had no social applications set up with Motoblur, this makes no sense. Why would it still need to be transferring that much data??? Anyone else experience this? I wonder if someone at Motorola technical support could tell me exactly what was being sent to Motoblur.