I have noticed an even more egregious alteration to BT's terms and conditions than their price increases. You are no longer subject to a 12 month minimum term. You are now subject to a rolling 12 month term in perpetuity, that is, the minimum term starts again each and every year.
Disgusting. No matter how many years or decades you have been with BT they will now penalise you if you leave.
(Remember this sort of outrage will be coming soon to a power company near you as well. The forces for competition have said that utilities no longer have to limit contracts to monthly ones.)