[Motorola Photon 4G] findthedr:
http://shop2.sprint.com/en/legal/legal_terms_privacy_popup.shtml?ECID=vanity:termsandconditions

Prohibited Network Uses. To ensure the activities of some users do not impair the ability of our customers to have access to reliable services provided at reasonable costs, you may not use our services in a manner that is unlawful, infringes on intellectual property rights, or harms or unduly interferes with the use of Sprint's network or systems. Sprint reserves the right, without notice or limitation, to limit data throughput speeds or quantities or to deny, terminate, end, modify, disconnect, or suspend service if an individual engages in any of the prohibited voice or data uses detailed below or if Sprint, in its sole discretion, determines action is necessary to protect its wireless networks from harm or degradation.

Examples of prohibited data uses: Sprint data services are provided solely for purposes of web surfing, sending and receiving email, photographs and other similar messaging activities, and the non-continuous streaming of videos, downloading of files or on line gaming. Our data services may not be used: (i) to generate excessive amounts of Internet traffic through the continuous, unattended streaming, downloading or uploading of videos or other files or to operate hosting services including, but not limited to, web or gaming hosting; (ii) to maintain continuous active network connections to the Internet such as through a web camera or machine-to-machine connections that do not involve active participation by a person; (iii) to disrupt email use by others using automated or manual routines, including, but not limited to "auto-responders" or cancel bots or other similar routines; (iv) to transmit or facilitate any unsolicited or unauthorized advertising, telemarketing, promotional materials, "junk mail", unsolicited commercial or bulk email, or fax; (v) for activities adversely affecting the ability of other people or systems to use either Sprint's wireless services or other parties' Internet-based resources, including, but not limited to, "denial of service" (DoS) attacks against another network host or individual user; (vi) for an activity that connects any device to Personal Computers (including without limitation, laptops), or other equipment for the purpose of transmitting wireless data over the network (unless customer is using a plan designated for such usage); or (vi) for any other reason that, in our sole discretion violates our policy of providing service for individual use. Unlimited Use Plans. If you subscribe to rate plans, services or features that are described as unlimited, you should be aware that such "unlimited" plans are subject to these Sprint Prohibited Network Uses.

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the highlighted text is BS in my opinion, but can be used to justify getting rid of you for any reason. That being said, (depending on where you signed up with sprint) you likely signed a service agreement for a plan and not specifically their Terms and conditions. Torrenting is not officially prohibited, and Sprint does not make clear how much data usage on an unlimited plan is prohibited. You should be able to get your deposit back with no ETF fees, and phones with clear ESN's.