Remember, this is your UNLIMITED USAGE broadband.
From Imagine's T&Cs:
Excessive Use
No system has unlimited resources, and we expect you to act responsibly when consuming resources on our system(s). If you consume excessive resources on our system we may suspend your access at any time without prior notice. Some access services are bound by a monthly allocation or download allowance.. You must comply with all current bandwidth, download, and other allocations on the service established by imagine. Use of Network bandwidth is expected to be reasonable and moderate. You must ensure that your activity does not improperly degrade any other user's use of the imagine service, nor represent an unusually large burden on the network. In addition, you must ensure that your activities do not improperly restrict imagine's ability to deliver the service and monitor the service and/or network.
Fair Use Policy – Broadband
A fair use policy applies to all WiMax Broadband Packages. The WiMax Broadband Service is a shared service and imagine reserves the right to manage the Network to ensure that all users get fair access to the Network. If users make excessive use of their WiMax Broadband Service their service may be restricted or they may be asked to subscribe to an alternative WiMax Broadband Package(s) more suitable to their usage. imagine at it’s sole discretion will define from time to time what constitutes excessive use of the WiMax Service(s) Once Customers exceed this level they will have the option to upgrade their WiMax Broadband Package(s) or their service speed may be restricted by imagine. In the event of the Customer refusing or neglecting to select an alternative WiMax Broadband Package(s), imagine may, upon due notice, terminate the provision of the WiMax Broadband Service to the Customer.
Will disclose from time to time? C'mon man up! Where is it lads?
I'm always dubious straight away of companies that aren't up front with you and refuse to disclose their usage limits (There are always usage limits, there's no such thing as "unlimited") All reputable companies disclose their real usage allowances. Even UPC will tell you that their real allowance is around 250Gigs a month. Companies that are afraid to do so are often reluctant because their real usage limits are often pretty low compared with their rivals.