Fighting Telemarketers: When Do-Not-Call List Fails, These Strategies Work If you've ever wanted to turn the table on telemarketers, here's how.

January 21, 2014 -- If you thought the creation of the "Do Not Call Registry" had solved the problem of telemarketers bombarding people with unwanted calls, think again.

Complaints about telemarketers have continued to climb since the Federal Trade Commission established the registry 2003. They now stand at an all time high -- almost 4 million in 2012 -- according to the FTC.

What can you do to fight back? Plenty, say experts: You can use new technology that detects and deflects telemarketing calls automatically. You can deliberately drive telemarketers nuts. Or you can do both.

Intrusive calls fall into two categories. The first are calls from legitimate telemarketers, in which the pitch comes straight from a real live person. Louis Greisman of the FTC's Bureau of Consumer Protection testified before Congress in 2013 that the Do Not Call Registry has been "tremendously successful" in protecting the 221 million people who have registered.

How to stop telemarketing calls

Changes in telemarketing technology, however, have introduced calls that fall into a second category. These fully automated solicitations -- so-called robocalls -- are sent out by the million by computers. A pre-recorded solicitation asks the consumer to respond by, say, pressing "1" on his or her keypad. Only after that does a human pitchman comes on the line. Robocalls, according to the FTC, are illegal -- unless the consumer has first given his or her express permission, in writing, to receive them.

Many robocalls peddle fraudulent goods and services that cause significant economic harm, Greisman said. In his 2013 testimony, he told Congress the FTC was using every tool at its disposal to fight them. For example, the Commission announced a challenge offering $50,000 in prizes to private-sector innovators who could come up with ways to block such calls.

Last April, software developer Aaron Foss won $25,000 from the FTC for a blocking system he calls Nomorobo. Up and running since October, the service is now used, Foss said, by some 45,000 consumers who subscribe to it for free. By Foss' estimate, Nomorobo currently is blocking 1.3. million automated callers.

Many such callers don't care about the Do Not Call list, Foss told ABC News either because they're overseas, and thus beyond the FTC's reach, or because it's easy for them, when shut down by authorities, to spring back into action in a new venue. They're more like email spammers than traditional telemarketers, he said.

Nomorobo piggybacks off a feature offered by most major phone carriers called "simultaneous ring." Foss said it's similar to call-forwarding.

When a consumer signs up with Nomorobo, he gets assigned a new phone number that rings simultaneously when somebody calls his existing landline or cell phone. When a robocall comes in, it rings once on the consumer's existing number and again, simultaneously, on the Nomorobo number, where an algorithm determines in a fraction of a second whether it's from a real person or from a robo-caller. If from the latter, a recording asks the caller to enter a number on their keypad.

Since no human being is yet on the line, no response is made, and Nomorobo dismisses the call before it can ring again. Thus, the consumer knows that any call that rings more than once is legit -- or at least that it comes from a real person rather than a robot.

The service is offered free to consumers. Foss makes money by charging commercial users a fee based on their call volume. Ironically, he said, call centers for legitimate businesses -- say, ones selling flowers through an 800 number -- get hit by robocallers the same way consumers do. They can't afford to have their lines tied up by automated calls, so they turn to Foss' company for relief.

David Lazarus, columnist for the L.A. Times, advocates a far more personal, more low-tech approach to stopping unwanted calls, which he calls "a little kooky but effective."

The idea was suggested to him by a Texas reader who pretends to respond enthusiastically to phone solicitors. "Tell me more," he says when the pitchman comes on the line. "Give me all the details." From that point on, the Texan's only goal is to keep the pitchman on the line as long as possible.

Asked to give a credit card number, the Texas man gives a false one, then relaxes while the pitchman attempts to confirm it. When it cannot be confirmed, he transposes a few digits, re-submits it, and rests again while the pitchman struggles to confirm the second number. Eventually the Texan, when through toying with his victim, invites the telemarketer to call again the next day, so they can try again.

Robocalls rise: How to fight back

In a later column, Lazarus, who calls this strategy a "reverse scam," invited readers to submit more strategies for making the lives of telemarketers a living hell.

A man in Glendale, Calif., submitted his strategy, which involves telling a pitchmen that he needs to get a pen and paper, then disappears for a bit. When he returns, he says he needs to get his wallet from the other room. Gosh, he says when he returns, that darn wallet must be in the car. Can you hold on a minute while I get it? And so on. He says with pride that while he's never gotten to the 30-minute mark with a telemarketer, he's often broken 20.

Telemarketers, notes Lazarus, are not fools. They don't want to waste their time any more than do consumers. After realizing they've been tricked into sticking with a fruitless call, they don't want to make the same mistake again. So, they stop calling, he said.

Consumers seeking further inspiration how they can prank telemarketers can find on YouTube in videos posted by comedian Tom Mabe, who has made a science of it.