Confirmed, T-Mobile hijacks DNS.
I am testing from my laptop tethered to a stock T-Mobile Note 3. Lookup of my IP address:
$ curl http://checkip.dyndns.org
<html><head><title>Current IP Check</title></head><body>Current IP Address: 172.56.20.69</body></html>
$ /usr/bin/whois 172.56.20.69 | grep OrgName
OrgName: T-Mobile USA, Inc.