Breach of privacy?

I work for Courierpost, which is the main money making enterprise for New Zealand Post. I work in the call centre tracking down packages and the like. When someone calls, a map of New Zealand pops up showing their location with a flashing red dot, and their phone number is displayed on the bottom of the screen. When I quote the phone number back to customers for booking and investigations, people are often somewhat affronted and startled that I have this information. It seems strange to me that here at courierpost we are not allowed to give out the numbers of depots or drivers, yet we have complete access to the location and contact details of our clients. I wonder if this is a breach of privacy? Probably not, but its still dodgey and puts the 'power' in the hands of the 'man' and makes the 'little guy' a tiny dot of money on a pixulated screen (I made that word up but you know what I mean)