Note that T-Mobile does deep packet inspection via transparent HTTP proxy on web traffic going through their network, especially if you use a prepaid device. You should read the OONI report [1] (from the Tor Project) on T-Mobile USA.
I had no idea this was limited to chrome, but having run into it two days ago, changing the user-agent string fixes it completely. I specifically used Android 4.0.2 (Mozilla/5.0 (Linux; U; Android 4.0.2; en-us; Galaxy Nexus Build/ICL53F) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30).
Hmmm I was going to investigate. So that seems to point to T-Mobile doing some sort of spying on one's HTTP requests? If that's the case why not block other non-mobile user-agents?