The EU top court's decision to strike down a transatlantic data sharing deal relied on by companies such as Facebook sends a "strong signal for fundamental rights protection in Europe," Germany's justice minister said Tuesday.

"Those who offer products or services in the EU must adhere to EU data protection rights -- no matter where the (computer) server is," said Heiko Maas.

In a major blow to US tech firms, the court said Tuesday the "Safe Harbour" agreement struck in 2000 between the United States and the EU did not sufficiently guarantee the protection of Europeans' personal data and must be struck out.