Why do so many applications require permission to read the phone state and identity? Why do so many applications require permission to read the phone state and identity?. Specifically:

Phone calls
   read phone state and identity


For example Quickpedia is a Wikipedia portal, but wants access to the phone. What is the explanation for this?
It allows the App to read a unique ID (a phone identifier named IMEI) that's associated with your phone. 

It can therefore help with copy-protection or the attempt to track the number of users.