I'm not privy to any statistics on the matter, but simply as an Android user I can tell you that Android applications can't dial numbers, send SMS, etc., unless

I'm not privy to any statistics on the matter, but simply as an Android user I can tell you that Android applications can't dial numbers, send SMS, etc., unless you explicitly grant them permission to do so -- and Android will tell you, plain as day, that the application wants privilege to access "Services that can cost you money".