It is straight out illegal to scan your ID or passport in Germany. There's just a few exceptions, like actual banks, and even they are not allowed to scan those documents, only to make a paper copy.
That is simply not true! You should check the current laws in Germany regarding this before you spread wrong information! If you are the owner of the ID/passport you are allowed to scan it as long as it is clear that it is a copy. You can do this with a watermark (copy) or just by copying in black and white.