Comment by Maakuth

This feature is nowadays called Privacy Guard and it works so well that I have it on by default for all apps. With the exception of apps that actually need to read my contacts (say WhatsApp), I have not had to disable it for any applications and haven't seen any complications. For example Facebook and Twitter apps, which require a whole rainbow of permissions, function just the way they used to. I've never made a lot of use of their location dependent features though and would expect those to suffer from being deprived of GPS data.