It's the fifth anniversary of the Federal Government's Do Not Call List.
To date, 150 million people have signed up to get their numbers off telemarketers' lists.
So how well is it working?
Amid widespread complaints about telemarketers, the Federal Government started the so-called "Do Not Call" list five years ago.
"In my opinion, it's been the most popular federal program in 50 years," said Tom Carter an attorney with the Federal Trade Commission.
"This rule really does work. I think over 75 percent of American consumers have placed their phone numbers on the do not call list."
The FTC has taken 35 companies to court and collected more than 16 million dollars in penalties.
We researched government records to find the companies that have paid the highest fines.
Topping the list:
Directv, the satellite tv provider, $5.3 million...
Craftmatic industries, the adjustable bed maker, $4.4 million...
ADT Security Services inc., seller of burglar alarms, $2 million.
Ameriquest Mortgage Company, $1 million.
And Bookspan, a book of the month marketer, $680,000.
"It can cost a company a lot of money. If you're a big company and make a lot of calls in violation of the rule, you are going to end up paying a big fine," said Carter.
Some people say the list just doesn't work.
"We are on the 'do not call' list. I have an unlisted number that I pay for. And they still call us. It's like, 'they have our number!'" said one person.
"If we get enough complaints about a particular company, then we open an investigation and look into it," Carter said.
But, he says, some calls from politicians or charities or companies you already do business with are allowed.
"People think there are violations when often there are not," said Carter.
How do the companies on the top five list respond?
Direct TV says its fine was the result of "independent third party relationships."
Craftmatic industries was bought last year by another company, which says it follows all telemarketing rules.
ADT Security Services blamed old computer software, and says it thought it was calling existing customers, as the rules allow.
Bookspan had no comment.