If it's a debit card that can be used as a credit card (and it must be, otherwise it couldn't have been used to pay for Linode), then it enjoys the same protection as regular credit cards when it's used as one.

Yeah, but it's one thing to deal with a line of credit that is maxed out by fraud and another to deal with an empty checking account.

Very true. If your bank gives you a separate savings account you can transfer the bulk of your money there and just use the card from the current account to limit your exposure.