Yesterday in a talk at 30C3, a historian discussed article 10 of the German 'Grundgesetz' (our constitution) whose logic is similar and which reads as follows:

> (1) The privacy of correspondence, posts and telecommunications shall be inviolable.

> (2) Restrictions may be ordered only pursuant to a law. If the restriction serves to protect the free democratic basic order or the existence or security of the Federation or of a Land, the law may provide that the person affected shall not be informed of the restriction and that recourse to the courts shall be replaced by a review of the case by agencies and auxiliary agencies appointed by the legislature.[1]

The logic sounds alike to me: Victims cannot know that they are being surveilled, and should they, under some circumstances obtain knowledge of the fact, take any real legal recourse against it. Fun fact: That article was imposed by the US.[2]

[1] http://www.gesetze-im-internet.de/englisch_gg/englisch_gg.ht...

[2] http://de.wikipedia.org/wiki/Deutsche_Notstandsgesetze (sorry, the English article doesn't cite any sources)