Amazon was completely right for banning acd_cli.

What they were doing is using a server in the middle for auth. But oh god the server started handing out the wrong keys so you might end up having total control of another acd_cli users account.

And when acd_cli got banned they (not acd_cli themself but users that modified the source) just used rclones app ID and keys to trick Amazon into thinking acd_cli was rclone. Then rclone got banned.

They (amazon) did say the problem with rclone was the keys were public since it is open source.