These Nine Companies Know More About You Than Google. And You've Probably Never Heard of Them.

Acxiom. Corelogic. Datalogix. eBureau. ID Analytics. Intelius. PeekYou. Rapleaf. Recorded Future.

You may not know any of these company names, but the companies sure know you.

And if they don't know you as well as they think they do, it could hurt you.

As a Federal Trade Commission report released today details, "data brokers" make a business out of collecting consumer information, but most consumers have little to no idea who these companies are, how the companies get their information or how they can protect their privacy.

The report hammers home the point that these companies know a lot:

Of the nine data brokers, one data broker’s database has information on 1.4 billion consumer transactions and over 700 billion aggregated data elements; another data broker’s database covers one trillion dollars in consumer transactions; and yet another data broker adds three billion new records each month to its databases. Most importantly, data brokers hold a vast array of information on individual consumers. For example, one of the nine data brokers has 3000 data segments for nearly every U.S. consumer.

The nine companies studied by the FTC all trade in the same information -- your information -- but what they do with that information varies.

Five of the companies sell marketing products, analyzing buying habits to classify different consumers and then sell that information to advertisers, who in turn use the data to more effectively target consumers.

It's the kind of industry that has exploded with the advent of the Internet and the easy planting of cookies in consumers' web browsers.

Four of the data brokers trade in risk mitigation products, used by lenders, landlords and others to verify that you are who you say you are.

Three of the data brokers offer "people search" products, offering consumers connections to old high school friends or allowing businesses to read up on competitors.

The FTC report notes the benefits of the services offered by these nine companies -- showing consumers more relevant advertising, reducing identity fraud, connecting people -- but also found a laundry list of problems.

Data brokers lump people into certain groups, with names like "Urban Scramble" or "Rural Everlasting," based on geography, buying habits and other identifiers.

The categories can be harmful as well as helpful.

The report considers "Diabetes Interest," a category that could be used by a sugar-free candy company to target useful ads, or which could be used by an insurance company to hike premiums.

The report also mentioned possible racially discriminatory undertones of some categories, including "Urban Scramble."

The massive information caches held by these companies also poses a security risk, the report notes, since hackers could be attracted to finding loads of personal information -- and potential keys to security questions and passwords -- for millions of people all in one place.

Perhaps the biggest problem in the under-scrutinized industry lies not with the data brokers, but with consumers.

They don't really know much about these companies.

They don't know how to check to ensure that their information is correct.

They don't know how to contest information or get sensitive data removed from their profiles.