[rbehrends]

In addition to what others have already said, the summary at the end is somewhat misleading. The directive does not lay down any rules for access by law enforcement or intelligence agencies. It only requires ISPs to store the data, not to grant law enforcement or intelligence agencies access. Such access would still be subject to national law (i.e., warrants and such).

The primary concern is not that data retention will directly lead to law enforcement going on big data harvesting operations, but that the chilling effect from having that data stored outweighs the practical benefits that law enforcement would derive from it.

A particular concern in Germany is the interaction with §98a+b of the Code of Criminal Procedure [1] and similar laws enacted by the states, which allow for not just particularized warrants, but dragnet searches ("Rasterfahndung"). While such a search still requires a (non-secret) court order and is allowed only under a limited set of circumstances, there is an undeniable chilling effect associated with it.

[1] http://www.gesetze-im-internet.de/englisch_stpo/englisch_stp...