Robocallers doing a number on the Do Not Call list

• New technology lets scammers cheaply and easily send out thousands of robocalls
• The Do Not Call Registry started in 2003 to address the problem of unwanted telemarketing calls
• There are more than 221 million numbers now on the Do Not Call list

The average monthly complaints from consumers who signed up for the national Do Not Call list but still are getting telemarketing calls have jumped 63% from 2011, according to data from the Federal Trade Commission, which maintains the list.

Much of the blame is on a proliferation of computerized robocalls, according to Lois Greisman, FTC's director of marketing practices.

Illegal robocall operations are taking advantage of increasingly sophisticated technology that has made it easier and easier to simultaneously send thousands of robocalls costing less than one cent per minute, Greisman says.

"It used to be, in order to blast out these calls you needed a big infrastructure, you needed a lot of service, a lot of computers, and now basically all you need is a computer and a voice over Internet protocol (VoIP) connection."

The Do Not Call Registry started in 2003 to address the problem of unwanted telemarketing calls. It was an immediate hit, adding more than 51 million phone numbers in its first year. Once a cell or landline number is listed, it stays until disconnected.

While registration growth has leveled out in recent years -- there are more than 221 million numbers now on the list --complaints have skyrocketed. Since last September, the FTC has handled an average of 308,000 complaints a month, a slight drop from a few record months early in 2012, and far more than two years ago.

Under the rules, only surveys, political calls, charitable requests and informational calls (such as a school announcing a weather delay) are allowed. And charity appeals must be direct, not from a telemarketer.

Greisman says FTC enforcement cases in the past several years have focused on scammers trying to sell bogus products such as extended auto warranties and credit-card debt reduction plans. But legitimate companies have gotten in hot water for violating Do Not Call numbers.

Along with being cheap and easy, robocalls can be the hardest to trace, says Sid Kirchheimer, author of Scam-Proof Your Life. Calls often come from foreign centers, and scammers increasingly use technology to "spoof" caller ID to display whatever number they pick, he says.

"The FTC is doing a great job for what they can do," he says. "(They) deserve credit – it's a really, really tough thing."

Since the Do Not Call program started, the FTC has filed 106 enforcement cases against companies and individuals who have violated the rules and has collected $81.9 million in relief and penalties.