You need to maintain useful contact information with appropriate authorities. Obviously with more significant organisations, the need for this is greater as the interruption of service to a larger part of the population increases. Particularly relevant to utilities, telecoms, banking organisations and the emergency services (and for smaller companies these might be on your list). Where attacks stem from the internet various authorities and providers may need to be called to action in order to divert /suppress / mitigate the threat. You can’t fix everything, but you can be ready should the need arise. This will help with business continuity and security incident management.