For fuck's sake. After about six months of getting overage notifications from Cox and being completely baffled at what was causing it, I finally figured it out. My computer was a red herring. I had Splunk set up monitoring logs, usage, watching Wireshark to see what was going on with my packets. Nothing pointed to a crazy process sucking down fatty packets. Then I started watching the lights on my router. I noticed when I disabled my WiFi on my computer, the little "i" icon was still flashing like crazy along with port 1, which was my Google TV appliance. Hrmmmm....
Then I came across this:
Google Play Music is the culprit. I am going to try clearing the cache, uninstalling, re-installing, and rebooting. We'll see if that marks an improvement.
Sheesh. That was a ridiculously convoluted solution to a ridiculously annoying problem.