Well, i personally think a huge chunk of international calls are recorded.
I just assume all my phonecalls and emails are recorded. ;)
It used to be that 100% of international calls to and from Blighty were recorded, although a relatively small proportion were actually listened to. I would guess the same is true today, except the volume of calls will have increased dramatically, and the sophistication of the techniques used to home in on "interesting" calls will have been massively improved as well.
To a large extent, analysis of the content of communications is a zero sum game though, as serious criminals, terrorists, financiers, businessmen, and other enemies of the people, will use pre-arranged but unnoticable codes to actually transmit the information, with the rest of the message being just innocuous camoflage to hide the fact that a message is being sent at all.
This is why the Forces Of Law And Order are so keen to order the retention of metadata surrounding communications - Even though you may have no idea whether a hidden message has been passed between two individuals, the fact that a communication path between them can be established means that you can start to focus your resources on more, rather than less, likely targets. This also, unfortunately, means that you need a legal framework that allows the investigation of individuals on no better pretext than they both have, say, friends who have a friend in common. If the theory of 6 degrees of separation is anywhere near accurate, you can see why the paranoid amongst the FOLAO quickly rationalise that they need untramelled access to any and all data on everyone. How they will distil this vast mountain of irrelevence into actionable data is a question I have yet to see any vaguely credible attempt to answer.
Where this starts to fall apart is when use is made of emergent properties of the data. For example, there is an embryonic plan in Britain to monitor the movements of all vehicles, all the time. This is ostensibly to allow vehicle taxation by road usage. All fine and dandy, until you notice that it will be possible to deduce from the road usage data (simple case) whether a given vehicle has been exceeding the speed limit, or (more sinisterly) whether a given vehicle has been co-proximate with a vehicle thought to have been used for "terrorism". In the first case, any government proposing to fine the hell out of people for playing with their favorite toys isn't going to be the government for long, and in the second case... Well, they can lock people up for 28 days without charge, or even a shred of evidence, already, already... All under the guise of keeping us safe!
Ever seen the film Brazil? :(
"What crime is it to rob a bank, compared to that of founding one?"
-- Bertold Brecht