While the BlackBerry Storm is technically a CDMA-based Verizon device, it's also a world phone capable of running on GSM networks like AT&T and T-Mobile. Generally, the GSM carriers don't mind what device you use, but it looks like T-Mobile may be cracking down on Storm users on its network. There are several reports this morning that Storm owners using T-Mobile are unable to use data services, and calls to customer service are met with either no help at all or a simple "your device is not supported." This seems very unlike T-Mobile, who is usually open with customers using any device on their network. They've even given support to iPhone users in the past. We're sure that there's some explanation for this, and we'll be sure to keep you updated as we learn more about the situation. Meanwhile, if you're a Storm user on T-Mobile, share your experiences with us in the comments.