[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] djkinetic:
Taken from the ATT Wireless Customer Agreement:

AT&T data plans are designed for use with only one of the following distinct Device types: (1) Smartphones, (2) basic and Quick Messaging phones, (3) tablets, (4) LaptopConnect cards, and (5) stand-alone Mobile Hotspot devices. A data plan designated for one type of device may not be used with another type of device. For example, a data plan designated for use with a basic phone or a Smartphone may not be used with a LaptopConnect card, tablet, or stand-alone Mobile Hotspot device, by tethering devices together, by SIM card transfer, or any other means. A data tethering plan, however, may be purchased for an additional fee to enable tethering on a compatible device. An Activation Fee may apply for each data line.

Consumer data plans do not allow access to corporate email, company intranet sites, and other business applications. Access to corporate email, company intranet sites, and/or other business applications requires an applicable Enterprise Data plan. Enterprise Email requires an eligible data plan and Device. Terms may vary depending on selected Enterprise Email solution.

AT&T RESERVES THE RIGHT TO TERMINATE YOUR DATA SERVICES WITH OR WITHOUT CAUSE, INCLUDING WITHOUT LIMITATION, UPON EXPIRATION OR TERMINATION OF YOUR WIRELESS CUSTOMER AGREEMENT.

6.2 What Are The Intended Purposes Of AT&T's Wireless Data Service?

AT&T's wireless data network is a shared resource, which AT&T manages for the benefit of all of its customers so that they can enjoy a consistent, high-quality mobile broadband experience and a broad range of mobile Internet services, applications and content. However, certain activities and uses of the network by an individual customer or small group of customers can negatively impact the use and enjoyment of the network by others. Therefore, certain activities and uses of AT&T’s wireless data service are permitted and others are prohibited. The terms and conditions of your use of AT&T’s wireless data service are set forth below.

Permitted Activities. AT&T's wireless data services are intended to be used for the following permitted activities: (i) web browsing; (ii) email; and (iii) intranet access if permitted by your rate plan (for example, access to corporate intranets, email, and individual productivity applications like customer relationship management, sales force, and field service automation); (d) uploading and downloading applications and content to and from the Internet or third-party application stores, and (e) using applications and content without excessively contributing to network congestion.

You agree to use AT&T's wireless data services only for these permitted activities.

Prohibited Activities: AT&T's wireless data services are not intended to be used in any manner which has any of the following effects and such use is prohibited if it: (a) conflicts with applicable law, (b) hinders other customers’ access to the wireless network, (c) compromises network security or capacity, (d) excessively and disproportionately contributes to network congestion, (e) adversely impacts network service levels or legitimate data flows, (f) degrades network performance, (g) causes harm to the network or other customers, (h) is resold either alone or as part of any other good or service, (i) tethers a wireless device to a computing device (such as a computer, Smartphone, eBook or eReader, media player, laptop, or other devices with similar functions) through use of connection kits, applications, devices or accessories (using wired or wireless technology) and you have not subscribed to a specific data plan designed for this purpose, or (j) there is a specific data plan required for a particular use and you have not subscribed to that plan.

AT&T’s Rights to Ensure Compliance. You agree that AT&T has the right to take any and all actions necessary to enforce this Section 6.2 if you use AT&T’s wireless data services in any manner that is prohibited, including, but not limited to, the following actions:

• AT&T may modify, without advance notice, the permitted and prohibited activities, and the optimization requirements for your wireless data services;

• AT&T may engage in any reasonable network management practice to enhance customer service, to reduce network congestion, to adapt to advances and changes in

technology, and/or to respond to the availability of wireless bandwidth and spectrum;

• AT&T may reduce your data throughput speeds at any time or place if your data usage exceeds an applicable, identified usage threshold during any billing cycle. AT&T will

provide you with advance notice of the usage threshold applicable to your data plan, or any changes to the applicable usage threshold either by a bill insert, email, text

message or other appropriate means;

• AT&T may use reasonable methods to monitor and collect customer usage information to better optimize the operation of the network. Details concerning the information that

AT&T collects about its customers, and how it uses and protects that information are addressed in the AT&T Privacy Policy (see att.com/privacy);

• If you are an AT&T unlimited data plan customer, AT&T may migrate you from the unlimited data plan to a tiered data plan and bill you the appropriate monthly fees. We will provide you with notice of this change at least one billing cycle in advance either by a bill insert, email, text message, or other appropriate means;

• AT&T may interrupt, suspend, cancel or terminate your wireless data services without advance notice.

Unlimited Data Customers. If you are a grandfathered AT&T unlimited plan data service customer, you agree that “unlimited” means you pay a fixed monthly charge for wireless data service regardless of how much data you use. You further agree that “unlimited” does not mean that you can use AT&T’s wireless data service in any way that you choose or for any prohibited activities, and that if you use your unlimited data plan in any manner that is prohibited, AT&T can limit, restrict, suspend or terminate your data service or switch you to a tiered data plan.

Its written and you agreed to the terms, any court would rule in favor of ATT and would not let you out of the contract. Sorry for the lengthy post.