Trust no one: How caller ID spoofing has ruined the simple phone call

I was walking through San Francisco when my phone buzzed. No caller ID, but the phone number was local, so I picked it up. Calling the man on the other end "irate" would be an understatement.

"Stop. Calling. Me." He bit off every word in anger.

Taken aback, I managed an eloquent, "Excuse me?"

"You keep calling me from this number," he said. "Stop it."

I knew what had happened, but it took five minutes to convince "George" (not his real name) that I was not the telemarketer who kept calling him using my number. He had already filed a complaint with the Federal Trade Commission, and I let him know that I would do the same.

The plain old telephone has become a significant security problem. While security experts tend to focus on online fraud, fraud via the phones has skyrocketed. In 2014, 54 percent of complaints to the Federal Trade Commission concerned companies contacting consumers by phone, up from 40 percent in 2013. Identity theft, attempts to collect fraudulent debts and scammers posing as someone else are the top types of fraud, according to the FTC report.

Because of voice-over-IP technology, fraudsters and criminals from anywhere in the world can reach out and talk to anyone. In addition, they can easily hide their identity, or pretend to be someone else. Because many consumer service companies--and government agencies--use a phone call as a way to confirm identity, this poses a major problem.

Police officers regularly have to deal with fake calls phoning in emergencies, such as hostage situations and shootings, that lead to SWAT teams showing up at a victim's house. A rash of so-called swatting has targeted popular video gamers who stream their playing live on the Internet. At the heart of the vicious prank is the ability of the assailant to spoof their number and masquerade as the victim.

Spoofing has also led to numerous scams against consumers and financial institutions, as well as allow hackers to sometimes abuse the password recovery features of online services and wrest control of a victim's accounts.

Spoofing is not all bad, which is why the feature remains. A victim of domestic abuse may want to hide her, or his, location or phone number. Other cases include a business owner who desires to make his, or her, cell phone appear as the business's main number to protect their privacy, according to Amanda Pietrocola, director of customer success at TelTech Systems, which provides the SpoofCard service.

"We have always worked to ensure all customers use it in ethical ways," she said. "Marketers are not breaking the law provided they abide by our terms of service and the Truth In Caller ID Act."

Consumers have few weapons to fight Caller ID spoofing. While services like Pindrop allow businesses to determine whether a call is likely from the reported number, there is no similar consumer service. The malicious pranksters who send SWAT teams to victims' residences are caught infrequently.

1. Don't trust Caller ID

The first line of defense is a healthy distrust of Caller ID, said David Dewey, director or research at Pindrop Security, which helps call centers and banks determine whether a phone call is fraudulent. About 1 in 300 calls are fraudulent, according to company's data.

"The best advice I can give on the consumer side is to trust no one," he said. "It does not matter who the Caller ID says the call is from, you cannot trust it."

Only provide information over the phone to someone you know and not someone who appears to be calling from your bank, the Internal Revenue Service, or some other company or agency.

2. Ask for a number to call the person back

As the FTC data shows, an increasing number of scams target consumers via their phone. Online fraudsters, for example, increasingly add a phone component to their schemes as a way of appearing more genuine.

Consumers should never just call a number in an e-mail and assume that the number is genuine. In addition, if a caller asks for your information, ask for a number at which to call them back. Investigate them online and then, if you feel confident, call them back and resume the call.