It is impossible to achieve complete confidentiality, even if you completely try to do it. If you will be very much needed, for example, the FBI, then they will find you, you can not even doubt it. The example of the silk road is very indicative here.
There is still a significant difference between personal right to privacy and privacy or rather anonymity that is being used or abused by criminals in facilitating or conducting some illicit activities, for which they must be punished by FBI.
If a person is trying to protect his privacy, it doesn't mean he is trying to commit a bad action that is illegal or dangerous for other people. What it means is that this particular person doesn't want other people to know how many funds he has or on what goods money is being spent. If these goods aren't illegal than he has the right to not tell everyone what he bought.