The inspector general of the NSA condemned Snowden for releasing information to the public instead of "going through channels" to report abuses internally in the NSA.

Reportedly the same inspector general retaliated against another NSA staffer who did exactly that, and he faces punishment for it.

As this example shows, reporting some illegality internally would be inadequate even if it were safe. We can't rely on internal reports to make the NSA obey laws, let alone to make it respect our freedom.