The hotel or gas station or rental car agency instigates the charge, and it isn't always a hold or authorization by the bank. I was making some work-related travel reservations tonight, and found this little tidbit in the terms of service and conditions for the cheapest car rental for a particular trip. This is floating cash by the company for a period of time that is totally unnecessary. As I wrote before, it is a scam.

ADVANTAGE RENT A CAR ACCEPTS DEBIT CARDS WITH A VISA/
MASTERCARD LOGO AS A FORM OF FINANCIAL RESPONSIBILITY
AT THE BEGINNING OF THE RENTAL. DEBIT CARDS MAY ONLY
BE USED FOR RENTALS OF ECONOMY THROUGH FULL SIZE CARS
AND MINIVANS. CUSTOMERS DEBIT CARD MUST HAVE AVAILABLE
SUFFICIENT FUNDS TO COVER THE COST OF THE RENTAL PLUS A
SECURITY DEPOSIT OF 300.00 USD IN ORDER TO SECURE THE
RENTAL. THIS WILL BE CHARGED AND NOT JUST AUTHORIZED
AT THE BEGINNING OF THE RENTAL PROCESS. THE DEPOSIT
WILL BE CREDITED BACK TO THE ACCOUNT UPON RETURN OF THE
VEHICLE AND SATISFACTORY SETTLEMENT OF THE CHARGES
WITHIN 10 BUSINESS DAYS.