Browse through DLA Piper’s extensive guide to data regulations and enforcement around the world and it’s clear that the United States stands out compared with more robust protections in places like Canada and Europe. (Elsewhere, protections are lesser or nonexistent.) Many European countries have central agencies dedicated to data protection. In France, individuals must give their consent before a data broker can distribute his or her data. In the United Kingdom, websites have to notify visitors of data-tracking software. Many European countries require data brokers to give individuals the opportunity to review their data profiles, and to show them how to access, change, remove, or otherwise object to the data that has been collected.

There is some dissonance to the fact that data protections in the U.S. are so slim compared with other regulations in other nations. Culturally, Americans prize the right to privacy. And there are U.S. sectors, like health care, where protecting personal data is paramount. But Americans don't even know which pieces of their personal data is swirling around out there. Your name, age, past addresses, political party enrollment, whether you own a home—sure, you might expect that kind of stuff is to be shared by marketers and others who deal in data. But data brokers specialize in inference, too, so they can figure out all kinds of super-specific details about who you are and how you live.

"For example, a data broker might infer that an individual with a boating license has an interest in boating, that a consumer has a technology interest based on the purchase of a Wired magazine subscription, or that a consumer who has bought two Ford cars has loyalty to that brand," wrote the Federal Trade Commission in a report on Big Data this week.

The FTC has been pushing for Congress to do something about free wheeling data brokers for the better part of the last decade. All this data collection is happening without consumer consent, and some the profiling that seems innocuous is actually harmful, the commission argues.

One person profiled as low-income might be inundated with sub-prime mortgage offers. Another person profiled as a motorcyclist might be flagged by insurance companies for higher rates. The categories into which consumers are sorted are incredibly detailed, and they’re based on a mix of government data (like the political donations you made), publicly available data (like the relationship status on your Facebook profile), and commercial data (like how Aquafresh Extreme Clean is your favorite brand of toothpaste, a nugget of data that’s linked to you because you swiped your CVS rewards card before paying).

Big data knows your net worth. It knows that you have a dog. It knows when you’re most likely to use a coupon. It knows your favorite brand of detergent. It knows your dress size. It knows about your last speeding ticket, and when you got the oil changed. It knows you have a hunting license. It knows whether you're pregnant—and often before you have a chance to share the news. The New York Times in 2012 told the alarming story of a teenager whose father angrily complained to Target for sending his young daughter promotional mailings for cribs and baby clothes. It later turned out the girl was pregnant, just as her data profile predicted. She simply hadn’t told her parents yet.