Basically (I would note), among the documents and data requested at hotels and similar (which already included personal address, telephone number and e-mail), guests will be asked for their bank account number.

I don't even remember my bank account number. Whenever I need it I just copy paste it from the online bank... I think there will be fun times trying to verify this information.

Seems this will require giving your bank account number to every accommodation on your trip.

What could possibly go wrong?