That's largely a myth these days:

Scheme rules mostly require issuers to extend a zero-liability policy to consumer debit cardholders.

Even if they wouldn't, there is a little-known debit counterpart to Regulation Z (which is the federal regulation affording you all the nice credit liability protections you might be used to) called Regulation E:

As long as you notify the issuer/bank within 60 days, your losses are also capped to $500. But since most banks don't want to lose a customer over a deductible in an edge cases (usually they can recover the funds themselves via a chargeback), the real loss is usually zero.