Although it sounds like James Bond stuff - I think that surveillance of this kind has been going on for decades. Nowadays, most companies have techniques and processes and abilities to monitor client/customer data quite easily. Of course, within the law, data protection act etc keeps that data of ours safe and the world goes about it's day ..
every now and again, a little snippet of info such as this pops out and people have a little 'im shocked' attack.. fine I understand we all dont want our private financial dealings, data, mail, correspondence, phone calls etc etc monitored but it's wrong to think you should be exempt or 'shocked' that it happens!
The last part of your message where you said 'next they'll be opening our mail' well, when it comes to email - they already do! and have been doing so for quite a while! Every email message sent to/from the UK at some point will pass through the publicly known about 'secret' GCHQ organisation run by the government. They have the ability to choose who to monitor if their special processes 'flag' up a possible issue/problem/suspect/traffic.
I'm sure in any quiet times, the monitoring staff there as well as any large company will have read/seen personal stuff and had a good old laugh at what they've seen/read!
Big Brother is watching.. and has been doing so for ages!!
Dennis! West London & Slough UK!