The National Cyber Security Centre Finland under The Finnish Transport and Communications Agency Traficom actively promotes the cybersecurity and reliability of 5G networks in collaboration with telecommunications vendors, network operators and information security researchers. During 2019 and 2021, we and our collaboration partners have organised 5G Cyber Security Hack events focusing on the cybersecurity of 5G technology and networks to promote collaboration and deeper understanding of the technology and its vulnerabilities. Together with this activity, we have promoted international discussion about a new type of cybersecurity collaboration among different players, such as national authorities, global technology vendors, end users, academia and the ethical hacker community.