https://www.theregister.co.uk/2018/10/26/belgium_finds_evidence_gchq_belgacom_hack_proximus/

GCHQ’s rumoured hacking operation against Belgacom came back into the spotlight yesterday after a local newspaper revealed more tantalising snippets from a Belgian judicial investigation into the attack.

Originally having come to light thanks to whistleblower Edward Snowden’s disclosures from American spy agency files he swiped from the NSA, the UK's signals intelligence bods are said to have hacked into the Belgian telco in order to monitor private communications flowing over its networks.