You must be referring to SEPA Direct Debit, which would be very risky to use to siphon funds. There's an 8 week no-questions-asked refund policy, 13 months for unauthorized transactions, if the payment fails (eg due to insufficient balance), the payee is charged a non-refundable cancelation fee. [0] And that's all separate from any legal troubles for fraudulent charges. I don't know why Germans use PayPal over SEPA, but I'd be surprised if SEPA Direct Debit was the reason.

[0] https://www.europeanpaymentscouncil.eu/what-we-do/sepa-direc...