[akavel]

As for one example, a fairly well known body has set up an official Mastodon server half a year ago:

https://social.network.europa.eu

"EU Voice is the official ActivityPub microblogging platform of the EU institutions, bodies and agencies (EUIs). Together with EU Video, it is part of an alternative social media pilot program proposed, and provided by the European Data Protection Supervisor (EDPS). The pilot program contributes to the European Union’s strategy for data and digital sovereignty that aims to foster Europe’s independence in the digital world.

EU Voice provides EUIs with privacy-friendly microblogging accounts that they typically use for the purposes of press and public relations activities."

A list of the official accounts present there: https://social.network.europa.eu/explore

A stream of recent activity from all the accounts on the instance: https://social.network.europa.eu/public