Where is information stored securely? On a private server not accessible from outside and protected by law or on foreign publicly accessible servers not protected by local laws?
So both the German and French governments host Nextcloud firewalled off from the internet. Others use things like a reverse proxy (City of Geneva). Most customers just run Nextcloud internet-facing, as that is the easiest if you want to collaborate and work remotely. We trust Nextcloud to be perfectly safe for that, at least as safe as any complex piece of software can every be, of course. We have a very active security team, the latest security measures and a bug bounty program where you get up to $5K for reporting issues to us.