Each client should find its callers' information exactly where it agreed to keep it, and nowhere else.
The first systems I supported belonged to other people's businesses. In June 1996, a month after finishing a computer science degree at Mirlochan University, I joined Brennacove Computer Services in Moncton as a service-desk technician. We supported law offices, the administrative staff of a regional hospital and several small manufacturers. A caller rarely cared which component had failed; they wanted to know whether their files were safe and when they could work again. I learnt to answer the second question honestly before guessing at the first.
An outsourcer sells its clients a promise about other people's information. Callers never chose us; they chose a utility, an insurer or a software company, and reached our agents because that company hired us. I judge our systems by whether such a caller would recognise the arrangement if it were explained to them, not only by whether a contract permits it.