The National Security Agency is not invading your privacy by vacuuming up your phone and Internet data.

Your privacy has already been invaded by Facebook and the other tech giants that collected the data in the first place.

If the government is turning into Big Brother in an effort to safeguard the homeland, then the tech companies are Rich Uncles, intent on getting ever richer.

And for Facebook and the others, data translate to advertising dollars.

Click on the word “privacy” at the bottom of “your” Facebook page and you are told, “We receive data about you whenever you interact with Facebook, such as when you look at another person’s timeline, send or receive a message, search for a friend or a Page, click on, view or otherwise interact with things.”

The company goes on to say, “When you post things like photos or videos on Facebook, we may receive additional related data (or metadata), such as the time, date, and place you took the photo or video.”

That’s right. When you post a cellphone photo on what you might call “your” Facebook, the company records exactly where you were when you took it, as well as where you were when you uploaded it, along with any comments you or anybody else has to offer. Facebook further records the websites you frequently visit as well as “the date and time you visit the site.”

Everything Facebook can glean from online tracing is matched with “behavioral data” that “partner” companies collect from seemingly everywhere, including debit card purchases and motor vehicle records and court files and financial records. One Facebook partner, BlueKai, confects “cookies” to track individuals who have shown online interest in particular brands.

“Sometimes we get data from our affiliates or our advertising partners, customers and other third parties that helps us (or them) deliver ads, understand online activity, and generally make Facebook better,” the company further reports.

Better as in more profitable, profit being the primary reason for gathering all this data. Personal details are what you tender in exchange for being able to do all the wonderful things Facebook offers. The Internet may have been created by idealists with no thought of profit, but these days it is strictly nothing for nothing, even if it sometimes appears otherwise. Do not think because Mark Zuckerberg wears a hoodie that he is any kind of Robin Hood.

Facebook emphasizes that it replaces identifying info with numbers before sharing your particulars with data-mining marketers. But Facebook itself still knows who corresponds to those numbers, as is demonstrated when a targeted ad appears on your page. Go online look and for a new mattress, and presto! an ad for Sleep-z pops up when you go on Facebook.

The NSA has been seeking to use that same data, along with phone records and seemingly everything else it can gather, to target terrorists. NSA chief Gen. Keith Alexander told the Senate Appropriations Committee on Wednesday that his agency’s super-surveillance has thwarted “dozens” of attacks. Alexander cited in particular a plot to bomb the New York City subway that seems to have been prevented less by mammoth databases than by some old-fashioned detective work by the British police.

Alexander also pointed to the case involving David Headley, who is said to have helped plan the bloody 2008 attack on Mumbai. It should be remembered that two of Headley’s three wives went to U.S. authorities to warn that he was involved in terrorism. They were ignored.

Maybe they should have issued the warning on Facebook.

Meanwhile, those who use Facebook should keep in mind how little privacy there is on Facebook for the NSA to invade. Anybody who imagines otherwise stands the risk of serious embarrassment.

Among them are those who took advantage of a Facebook offering a “Bang With Friends App.” The page pledges, “Never will anybody know which friends you have chosen, nor does anybody see that you have used this app.”

But, as CBS Money Watch has reported, you need only go to to see who among your Facebook friends signed up for the app before 2013. (Apple yanked it from the App Store in May.)

At least the NSA is trying to thwart those who are much less interested in banging friends than in blowing up their enemies. The enemies being us, the land of the free, where Big Brother is still scarier than the Rich Uncles.