Permissions is the simple, albeit flawed, answer.
It doesn't matter if your TV makes a noise if nothing is listening for it.
Deny access to your microphone. There are very few good reasons for an app to access it.
Use your firewall. Your data belongs to you, there are few good reasons that an app should be connecting out to services like SilverPush.
Unfortunately, this usually requires domain knowledge ("who is trustworthy?"), which is why the answer is flawed.
