The Shaw AUP loosely defines abuse as the following:
"You must comply with the current bandwidth, data storage and other limitations on the Services.
You must ensure that your activity while using the Services does not improperly restrict, inhibit or degrade any other customers use of the Services, nor represent (in the sole judgment of Shaw) an unusually large burden on the network itself, such as, but not limited to, peer to peer file sharing programs, serving streaming video or audio, mail, http, ftp, irc, dhcp servers, and multi-user interactive forums."
"Shaw reserves the right to set specific limits for Bandwidth Usage and charge for excessive Bandwidth Usage for residential Services at any time. In addition, you must ensure that your activities do not improperly restrict, disrupt, inhibit, degrade or impede Shaws ability to deliver the Services and monitor the Services, backbone, network nodes, and/or other network services."
Simply put, Shaw can take action to limit bandwidth use, and can impose excess bandwidth fees or other restrictions such as throttling.