(NewsNation) — A nightmare scenario: One man had hundreds of thousands of dollars stolen in mere hours.

A new scam is making its way into your bank accounts and stealing your personal information.

An alert is being issued about the theft of your cellphone number. The scam is called a “SIM swap” and the FBI is warning Americans as it sweeps the country.

In 2021, the FBI received more than 1,600 (1,611) SIM swapping complaints, costing victims $68 million.

The Federal Communications Commission considers this scam a type of cellphone fraud, defined as the “unauthorized use, tampering or manipulation of a cellular phone or service.”

Here’s how it works:

A person gets hold of your wireless password through a data breach or phishing scam and then tricks your mobile carrier into switching your number to a new SIM card.

Scammers can also physically steal the victim’s SIM card from the victim’s phone and use it in their own mobile device.

Once that happens, scammers can gain access to your accounts by requesting a new password associated with your phone number. From there, they can empty your bank accounts, trading accounts and anything else they’ve gained access to — including the victim’s private texts and calls.

Most victims say it happens so quickly, you won’t even know until you’ve already been robbed.

“My phone said, ‘no service, sim card.’ and I didn’t even know what a sim card was. I lost everything in a matter of hours.,” said “SIM swap” victim Dan Clark.

ways to protect yourself:

• Use multi-factor authentication features for any accounts that offer them.

• Even though it is convenient, don’t save important passwords, like those for your bank accounts, in your phone. Use face ID or your fingerprint ID to protect your accounts.

• Don’t ever give out your account information via email or phone. Always call your carrier directly if anyone requests your information.