It is always a matter of scale. You can get the fingerprint of anyone (relatively) easily, but not everyone. So the problem only arises when it is done in mass

It is always a matter of scale. You can get the fingerprint of anyone (relatively) easily, but not everyone. So the problem only arises when it is done in mass or more generally when it can be used by centralized entities of any sort. The wider question is, if this can be avoided at all. But I think we should at least try, because this kind of data can so easily be misused and at one point in time we were already aware of that, but forgot in recent times.