I haven't ever seen illegitimate direct debit. I guess you need to have an actual business to issue direct debit orders and bank will show you the door and freeze your money if you start doing funny things. I guess.
Probably the dreadful R word has something to do with it, go figure.
On cards we also have limits and the only time I saw something happening was after being unfortunate enough to pass through ~~the ghet~~ the glorious capital of our continental Empire, majestic city of Brussels. That time the bank tried their best to call me.