If circumstances are such that monitoring one customer means all customers have to be potentially monitored then that, in practice, is the way things are. After all the TSA operate on exactly the same principle.
It may not, in some airy-fairy, hippy, juvenile world view, be "OK", but again, it is the way things are.
It may not, in some airy-fairy, hippy, juvenile world view, be "OK", but again, it is the way things are.