but what, and how?
One of the problems facing legislators is the necessity to be able to identify - and subsequently prosecute the perpetrators of this kind of thing. It isn't enough merely to say that BT must be held to account - they aren't really in a position to know when a person has deliberately dialed into a premium rate number and when he/she hasn't. Any change in the law has to take into account the fact that publicly owned companies must be allowed the freedom to develop their business and maximise their profits with as little intereference from the state as possible. If a few unscrupulous people decide to take advantage of the system to fleece innocent subscribers it's regrettable, but it isn't sufficient cause to take draconian action that might penalise legitimate premium rate users.
The Computer Misuse Act of 1990 was drafted with hacking in mind, and no offence exists when a dialer is downloaded because the computer owner invariably agrees to the installation - albeit without realising what's going on. The act of agreement is sufficient to take the installation outside the Misuse act's provision that covers Unauthorised modification of computer material - or at least I think it does.
If a dialer is covertly downloaded and installed - without the owner knowing or agreeing - and said dialer subsequently alters the way the computer works (which is surely does if it changes the dial-up number without the owner knowing) then I would argue that a law already exists to deal with it. Under the CMA there's an offence - punishable with up to 5 years imprisonment - of attempting to modify computer material with intent to impair its operation. I would argue that the person who causes the dialer to be downloaded and/or installed IS attempting to impair the operation of the machine.
We'll gave to wait and see, but I hope it doesn't take too long before there's some action; the internet comes in for enough criticism as it is, we don't need this.
Finally - let's not be too quick to censure BT on this (not that you have Pesala) - it's not their fault.