Forget Childish Gambino.
— BBC One (@BBCOne) August 27, 2018
And thus, we can assume, they had (have?) access to a lot of European instances and personnel, both residing here in Belgium and roaming using BGC’s network.
If GCHQ was indeed the agency concerned then this investigation is unlikely to go anywhere and the most that can be expected is some sort of diplomatic complaint from Belgium to the UK, its EU and Nato partner.