...nothing's really changed...
We have always suggested to customers in the terms and conditions that if an account is to be closed within the first twelve months of service, an exit fee to cover the cost of line activation would be charged: for customers who migrate to us from another ISP, this is £20 and for those who are having their lines enabled for ADSL with us for the very first time, this is £85 (clause 1.14 under 'definitions').
When ADSL accounts are requested to be closed, the customer is charged any subscriptions due within the notice period which is 28 days - this also hasn't changed and despite the fact that the service is now advertised as a yearly contract, the customer if choosing to cancel is not charged any remaining subscriptions to make up the full year, for example.
The way accounts are closed and the amount customers are charged to cancel their account within the first twelve months has not changed now in any way from how the service was advertised when you joined Fast4: however, since a charge is due within the first twelve months for ADSL accounts, Fast4 have used the term 'contract' to ensure customers are fully aware of the penalty that may be charged on their account for an earlier cancellation - however, the actual process of cancellation has not changed, nor has the amount a customer would be charged.
The FUP and it's implementation in the members area as a 'traffic light' system is an extension of the Network Abuse Policy that has been present within the terms and conditions for some time: we've always advised customers thtat heavy bandwidth usage for continued periods of times is detrimental to the network (indeed, from the 5th October, customers abusing this found their accounts restricted for the first time as this clause was enforced) and by helping customers to identify if their accounts are being used in this fashion, the members area is being updated to show you where your usage stands in terms of network traffic as the whole.
There isn't a limit to how much a customer can use as such - the problem was and always has been the few customers who use their connections continually for video streaming, binary downloads or peer to peer downloading - the constant heavy bandwidth usage that's required for these tasks can affect all users.