It should be noted that this ruling is related to the predecessor (DRIPA) to the current Investigator Powers Act (IPA), however it sets a precedent for the IPA to be challenged.
The ECJ has agreed with the British High Court's previous ruling on DRIPA, so should still carry weight regardless of Britain's status within the EU (unless further legal amendments are made post departure, such as the replacement of the Human Rights Act).
The ECJ has agreed with the British High Court's previous ruling on DRIPA, so should still carry weight regardless of Britain's status within the EU (unless further legal amendments are made post departure, such as the replacement of the Human Rights Act).