There was a time when only people with money to hire a detective could dig into someone’s life. Now, dozens of companies have sprung up that will prowl into a person’s past for as little as $ 2.

This shift illustrates a fundamental change in the economics of privacy: it has become cheap and easy to pry into the lives of others at the same time that protecting our own lives has become time-consuming and expensive. A look at two companies — one that sells your data and another that protects it — shows the business and policy lessons of this new reality.

Intelius: $ 1.95 for your address, family and phone number — $ 50 for the full package

Intelius is one of the biggest companies in the industry known as “data brokers” or “people search.” You’ve likely encountered one these companies after Googling a person’s name and discovering a site that offers to tell you more about the person for a fee.

These companies compile personal profiles by using computer tools to mash together public information that, in the past, would have been located in a variety of physical places like a county clerk’s office or the Department of Motor Vehicles. Many brokers also add additional layers of information garnered from public internet sites like Facebook or from financial service firms.

The result can be staggeringly complete. I fed my girlfriend’s name and city into Intelius and it correctly listed her age, the places she had lived in the past and the names of her parents and sister — and that was just the free version. Here’s a screenshot (I’ve replaced my girlfriend with a more public figure, Brooklyn congresswoman Yvette Clarke):

This is just the beginning. For $ 1.95, it is possible to purchase Yvette’s birthday and phone number. And for a little more money, Intelius will sell everything from her social network history to the identity of her neighbors:

This flood of personal data is disconcerting but it’s also very big business. An Intelius employee said the company’s annual revenue is over $ 140 million. Dozens of other companies like PeopleFinders and BeenVerified offer similar services.

Abine: $ 99 to hide from the internet

Many people, understandably, don’t want Intelius to sell their personal history to other people. While they have the option of asking the company to remove them from its records, they can also pay a third-party like Abine to do it for them. The Boston-based start-up offers a service called DeleteMe that will ensure a client’s name doesn’t appear on Intelius or on more than 50 other data brokers.

According to Sarah Downey, an attorney with Abine, the service is helpful because many data brokers require people to jump through a series of hoops (such as sending a letter and fax) to remove their names and, in some cases, the brokers will comply with the request but simply re-list the person again months later. DeleteMe, users of which include the California Judges Association, does the work of removing a person’s name and monitoring the brokers to ensure it doesn’t reappear.

Downey says the danger of data brokers extends beyond potential stalkers or noisy co-workers.

“Not only is it creepy, but having your information out there increases the likelihood of identity theft,” she said, explaining that some brokers are the first stop for criminal syndicates who purchases big batches of names. (Intelius is not one of the companies that sells in bulk).

In addition to identity theft and stalking, the data brokers can give rise to another problem: career or housing discrimination. Last month, data broker Spokeo agreed to pay $ 800,000 to settle accusations that it was selling credit histories to recruiters and employers in violation of the Fair Credit Reporting Act.

The Spokeo case illustrates how some companies look to data brokers as a tool to avoid choosing the wrong employee or tenant — even though federal and state law strictly regulates how such data can be used.

Time for a ‘Do Not Collect’ Law?

It’s important to remember that there’s nothing illegal about compiling information. Just as a busybody can visit libraries, courts and public offices to collect information about a neighbor, companies like Intelius can use computers to do the same thing.

Jim Adler, the chief privacy officer at Intelius, argues that the company’s activities are not only legal but useful. He says there are dozens of legitimate consumer uses for Intelius’ data, such as organizing family reunions, journalistic investigations or airlines returning lost luggage. Adler adds that the age of big data means a ”get me out of the internet” attitude is unrealistic.

If this is the case, people may have no choice but to rely on services like DeleteMe or Intelius’s own True Rep service to prevent others buying information about their personal life. In the case of True Rep, the service offers subscribers a way to delete their current phone number and address and to receive alerts when new public records appear (though a cynic may wonder if Intelius offering True Rep is like a locksmith breaking into your house to sell you a lock).

There is a problem, however, with asking citizens to rely on solutions like DeleteMe or True Rep to guard their privacy. Namely, this ‘pay for privacy’ approach doesn’t acknowledge the new economic imbalance in which personal data is cheap and anonymity is expensive. Can every individual afford to pay off companies that can harvest and sell their data for next to nothing? Intelius’s Adler suggests paying data brokers for privacy is like paying the phone company to keep your name out of the white pages. But this analogy doesn’t take account of the fact that the ‘people search’ companies disclose much more information than the phone book.

Downey at Abine says there is a better solution than paying for privacy. She says that the data broker industry needs to create a simple one-stop shop that allows people to unplug themselves once and for all. Downey says that if the data companies don’t begin self-regulating, the government will step in and create something like the ‘do not call’ registry that is putting an end to telemarketing. Adler agrees that there is room for more self-regulation in the data industry and says that Intelius is in favor of practices that will leave room for “responsible innovation.”

In the bigger picture, a ‘do not collect’ system would help stanch the flow of personal information that is migrating online but that may not be enough to put the data genie back in the bottle. As my colleague Derrick Harris explains in his comprehensive “Now’s the time for a Web 3.0 right to privacy,” the rise of facial recognition technology and social networks means that even individuals who delete their data may be uncovered all the same.

(Images by Semisatch, Orla and Katie Little via Shutterstock)

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