Note that for some devices (e.g. Raspberry Pi), at the end of the flashing process the tool tries to customize the SD card e.g. it configures a hostname or WiFi. And with a cloud-init enabled image ...

Fail2Ban scans log files like /var/log/auth.log and bans IP addresses conducting too many failed login attempts. It does this by updating system firewall rules to reject new connections from those IP ...