* Digital privacy campaigners hail decision
* Prosecutors disappointed, ministry considering appeal
* European worries over mass surveillance (Updates with reaction from KPN telecom and prosecutors)
By Toby Sterling
AMSTERDAM, March 11 (Reuters) - A Dutch court abolished a law on Wednesday requiring telecoms companies to save tracking data on their customers for the police, a ruling hailed by privacy activists but decried by prosecutors who said it could hit investigations.
Digital rights group Bits of Freedom said it hoped the order would set a precedent and stop the systematic saving of information on people’s movements.
But the Dutch national public prosecutor’s office said it was “disappointed” and the Justice Ministry was considering an appeal.
The data “is of great interest for the investigation and prosecution of many thousands of crimes ... That the requirement to preserve it is gone ... will have a large impact on future” cases,” it added.
Reports in 2013 that United States may have bugged the phone of German Chancellor Angela Merkel raised concerns across the continent over the risks of mass government surveillance.
The European Union had issued a directive in 2006 requiring states to save telecommunication data for at least six months and no more than 24 months.
But that system was thrown into doubt in April 2014 when the Court of Justice of the European Union found it was invalid.
Judge Gerard van Ham wrote in Wednesday’s ruling that the court “realises that putting the law out of commission may have far-reaching consequences for the investigation and prosecution of crimes”.
But that did not justify allowing the violation of privacy that widespread collection of data on phone calls and Internet traffic entailed, he said.
“We’re still working, but we’ve cracked open a bottle of wine at the office today,” said Bits of Freedom spokeswoman Daphne van der Kroft, reacting to the ruling.
KPN, the largest telecommunications company in the Netherlands, said the ruling was “pretty clear.”
“We have to stop collecting data for police use, and we will,” said spokesman Stefan Simons
He noted that prosecutors could still get a court order to request data be collected on suspects in advance — and authorities could also ask for data that KPN stores for its own uses.
“There is some information that we have to collect, for instance data we need for billing, or in order for you to receive a call on your cell phone” he said. (Editing by Andrew Heavens)