You've been hearing a lot lately about the extent to which the NSA has been gathering personal data on ordinary people, but did you know that Wal-Mart (NYSE:WMT) is doing the same? Did you know that Target (NYSE:TGT) can tell you're pregnant before you've necessarily told all your friends, and it ain't because your bump is showing?

Yup. No matter how tight the privacy settings are on your Facebook page, your private information is out there in the hands of a lot of folks who don't necessarily have your best interests at heart.

Who shares your data?
Two things happened this week that may seem contradictory at first glance. A report revealed that Wal-Mart has data on more than 145 million Americans, which it shares with 50 third parties. Moreover, the company is ardently resisting efforts to tighten up privacy regulations for consumers.

At the other extreme, Microsoft (NASDAQ:MSFT) announced a broad new set of privacy features specifically aimed at shielding Microsoft customers from what the company described as "government snooping." Microsoft has also been fighting the government in court, trying to secure the right to be more transparent about what the company shares with the NSA about its customers.

Who profits from your data?
Why such different approaches from these companies to data privacy issues? It turns out that it has everything to do with who profits from your information, which means that the issue varies dramatically from one industry segment to the next. Wal-Mart is a retailer, while Microsoft is a global computing giant, and that distinction changes everything about the landscapes in which they operate.

Watch the video below to learn more about why companies respond so differently to this controversial topic. We'll also tell you more about how Target knows when you've got a bun in the oven.

Sara Murphy has no position in any stocks mentioned. Follow her on Twitter @SMurphSmiles. The Motley Fool owns shares of Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.