There’a a key nugget buried in this morning’s New York Times story about how Facebook is going to give its users the ability to see why certain ads are targeted to them. Starting this week, the Times reports, "the company will tap data it already collects from people’s smartphones and other websites they visit to improve its ad targeting. Users can opt out of such extended tracking, but they will have to visit a special ad industry website and adjust their smartphone settings to do so." In other words, Facebook is giving users a glimpse of what marketers already know about them, but it is also going to give marketers more information about users—which makes sense, given that Facebook’s business model is largely built on the data you provide. Facebook wants to know where you’re from, how old you are, who you’re friends with, what industry you work in, your likes, your relationship status, where you vacation, etc., etc., in large part because marketers want to know those things. I’m reminded of this every time I log on. I never told Facebook my hometown, but it’s been guessing ever since—New York City? Philadelphia? Honolulu? Baltimore?—in a box that appears prominently on my profile page. I keep avoiding answering, mostly because I relish the fact that there’s at least something Facebook doesn’t know about me. There’s plenty else the site has figured out. (I wrote recently about the time Facebook guessed what shoes I was wearing.) And though it seems like a plus that Facebook is giving users the chance to click through their "full marketing dossier," as the Times put it, the move raises a question that people have been asking for a long time: Why don’t individuals in the United States already have access to this kind of information about themselves? Elsewhere, people have to give their consent before a data broker like Facebook or a social analytics firm can distribute personal information about them. There are regulations in several European countries that mandate individual access to data profiles, and give people the power to change or remove information about them. In Argentina, data tracking companies that want to collect personal info—that is, anything about an individual that isn’t found in publicly available government databases—have to tell a person why they’re collecting the data and who will receive it, as well as detail the individual’s rights to access, change, or remove their data. In Chile, individuals have to give written consent to data brokers who want to create marketing profiles about them based on personal information. No such protections exist in the United States. The Federal Trade Commission has been pushing for such measures—last month it issued an extensive report on the scope of data collection in the United States, including recommendations for consumer protections. Congress has introduced a couple of bills that would let consumers opt out of data collection, or otherwise be notified about the extensive personal profiles marketers collect. The data-collection machine in the United States is a behemoth. Data broker Acxiom told the FTC it has some 3,000 data segments for nearly every consumer in America. Datalogix, which works with Facebook, has personal information about almost every U.S. household, according to the FTC. The shift toward transparency at Facebook may be small, but it is significant. From the Times: Facebook will be the first major Internet company to show consumers how a specific ad for, say, a new television, is linked to a particular assessment of their interests, such as a fondness for electronics. Giving users the ability to alter their ad profiles gives individuals at least slightly more control over their interactions with Big Data. And maybe the shift toward data transparency at Facebook will prompt other companies to follow, or even encourage Congress to act on measures to protect consumers on a larger scale. In the meantime, though, the relationship between companies and your data hasn’t changed. According to the site aboutads.info, there are at least 99 companies customizing ads for my browser as I write this—that’s customization based on my personal data and online (and offline!) behaviors. Data collection techniques used by corporations and governments are only becoming more sophisticated and far-reaching, and we’re only just beginning to understand what they know.