Let's ask the users to paste the signing status of their ownCloud instance. I went this way instead of simply asking "Has your instance passed code signing?" as a lot of users would probably simply answer "Yes" here.
If they paste the results of http://example.org/index.php/settings/integrity/failed the expected output is "No errors have been found.". Everything else indicates they tampered with their installation.
projects / nextcloud-server.git / commit