Spoofers make victims think they're getting a phone call from a different number, like that of a bank or credit card company. Under false pretense, they try to get the person on the other end of the line to give up information like a social security number or credit card number.

Sen. Bill Nelson, D-Fla., is sponsoring a bill to ban transmission of false caller ID numbers. A similar bill has sailed through the house.

"Criminals have used caller ID spoofing to hack into a bank account and into voice mail accounts to steal sensitive personal information," he said.

Kevin Mitnick, once a notorious Internet hacker, is now an information security consultant tracking spoofers. He said spoofing is a relatively simple scam to pull off.

"You can go on the Internet and type in caller ID spoofing and find a number of services that offer this service for a small fee," he said. "Definitely, it's a threat."

Tips for Consumers

Sue Macomber, a victim of credit card identity theft, dealt with the consequences of scammers in the past. So she was wary when she got a phone call supposedly from the state comptroller's office. In fact, it was a spoofer showing a phony caller ID.

Now Macomber is a consumer advocate, warning people to guard against ID scammers so they don't endure the same misery she did.

"I think it's as sleazy and low as people can get," she said. "You can go through the most unbelievable nightmare of your life."

Consumers can prevent themselves from becoming spoofing victims. Experts offer the following tips:

Never give out personal information over the phone or online unless you know exactly who you're dealing with.

Banks, credit card companies and other businesses never call to ask for personal or account information. Usually they already know it.

If you have any doubts about who's on the phone, ask for a number to call them back.