Re: Blackberry is considered a "mobile operator"?
The numbers aren't huge, IIRC, but out of all the users a significant number were government types
The problem that Pakistan has is that it has no genuinely functioning democracy (and little cultural acceptance of Western democratic structures), and the security services (ISI) are a power player in their own right, widely believed to be in cahoots with domestic terrorists, insurgents in Afghanistan, and supporting (for example) the Mumbai terror attacks.
The difficulty of this request is that it may not be clear (even in Pakistan) who is the prime mover of the request, why they want this, nor what they will do with the intelligence. The worst and perhaps most likely case is that the ISI want the powers to cement their own power base and to subvert what limited democracy does exist, whilst continuing to support terrorism and failing to stop meddling in Afghanistan.
I'd guess that BB asked the Canadian and perhaps US authorities about this, and were told that it was a very bad idea, so bad that retreat was better than acceding to the request.