China listening in on Skype - Microsoft assumes you approve
The thing that bothers me most about this is that they aren't even admitting to it. I'm pretty sure they do it in a lot more countries than China, including US. The very least they could do is tell people which governments are requesting this of them, and how many times they are doing it every 3 months or every year, the way Google shares this kind of data in their "transparency report". They owe it to their own users.
If you're looking for a secure open source (meaning if there's a backdoor, you'll know about it), I recommend Jitsi, which works on Windows, Mac and Linux, and uses encrypted video-calls, too. For mobile chatting use any OTR-enabled app. They are all compatible with each other for secure chatting. Users don't have to use the same OTR client. There are plenty of them out there. IM+ is one of them, and is on all mobile platforms, including BB and WP: