"Hi, I am calling from you local phone company. We know that you have been talking with your friends about getting a new car. Have you considered a Ford from Fred Blogs your local dealer ?"
If you had call like this you certainly would be outraged. How can a phone company justify wire tapping you so that they can make money pushing adverts ?
If you postman said "I have read your banks statements, may be you should consider a loan from Sharky loan company." You would be concerned. We take for granted the separation between communication providers and processors.
We expect our phone calls, mail and web activity to be secure end-to-end. An agreed exception is hunting for criminals but even in that example "Probable cause" has to be established before the interception occurs. However such interception is essentiality what BT/Phorm have been doing and plan to do across the data network. By reading your web browsing habits BT and other ISPs plan to deliver content targeted adverts.
Interception of phone and data communications is a key privacy area, in which the few public safeguards have been hard to secure and protect. To see a blatant example of illegal interception just brushed under the carpet for commercial reasons is hard to stomach.