John Leyden writes in The Register:
Comms data retention is ineffective for the prosecution of serious crime, according to a study of German police statistics by local privacy activists.
Germany implemented a European Union directive in 2008 requiring telecoms operators and ISPs to retain data about customers’ communications, including numbers called or email addresses contacted along with their times and dates.
Police and other law enforcement agencies had the option to acquire this data in the process of investigating serious crimes, until last year when a German constitutional court struck down the measures on the basis that they interfered disproportionately with fundamental rights.
An analysis (PDF) of Federal Crime Agency (BKA) statistics, published by German privacy rights group AK Vorrat, suggests the loss of data retention will make little practical difference to police.
The analysis, available here, concludes:
The analysis reveals that data retention, while in force, did not make the prosecution of serious crime any more effective. With data retention in effect, more serious criminal acts (2009: 1,422,968) were registered by police than before (2007: 1,359,102), and serious offences were cleared less often (2009: 76.3%) than before the retention of all communications data (2007: 77.6%).