RIPE NCC, the Regional Address Registry that assigns IP addresses mainly to ISPs, has published a “Transparency Report” on requests from Law Enforcement agencies.
In 2012, the RIPE NCC received 21 information requests from Law Enforcement Agencies (LEAs), three of which were accompanied by non-Dutch subpoenas.
The requests were either about information that is publicly available or about information the RIPE NCC does not possess. Finally, some of the requests were not directly related to the activities of the RIPE NCC and therefore irrelevant to the RIPE NCC.
A breakdown of the reasons is available at the link above.