(RNS) So now we know that, behind the scenes and buried deep, clever technology is tracking our lives through the mobile devices we gush over and computers we depend on.

Firms that we want to trust are tracking who we are, what we buy, what we search for, and where we go. They sell that data to advertisers and make it available to government snoops without much resistance.

As a result, our personal data get poured into vast data pools, where shadowy firms with data-mining technology can sift, sort and sell virtually everything about us.

Meanwhile, The New York Times reports that cereal makers are selling computer games to children that actually are “advergames” hawking a product. Content farms churn out phony content in an attempt to beat Google’s search algorithm. Apple’s iPhones record users’ movements and make the data vulnerable to identity thieves.

In a one-year period, Sprint Nextel provided law enforcement agencies with phone users’ location data 8 million times. On “NCIS,” such tracking seems clever; in real life, it seems spooky.

From an ethical perspective, it hurts to see Silicon Valley in such tawdry company as Big Tobacco, which remorselessly preyed on people, got caught in knowingly selling cancer and emphysema, threw up a legal and lobbying smokescreen, and then resumed preying.

Is this the best that bright young minds can do with these magical tech tools: deliver eyeballs to advertisers, children to predators, and finely tuned data to government?

It hurts because I admire their ingenuity, enjoy their gadgets, applaud web-based communications and think e-commerce has great benefits. The Internet can be such a powerful tool for the good. To see a talented generation chasing multimillion-dollar paydays for doing little more than a carnival huckster hawking a Veg-O-Matic is tragic.

Another cohort seems to have missed Ethics 101, in which we study the good, not the profitable; and consider the social contract, not ways to manipulate people against their best interests.

An Ethics 101 class would consider Google’s philosophy-“You can make money without doing evil”-and study how the lure of $26 billion in annual online advertising has erased the “without doing evil” clause.

The ethics class would study Facebook’s high-profile CEO Mark Zuckerberg, who still plays the role of groovy geek wearing a hoodie while his firm ramps up a lobbying office in Washington to make sure that Congress doesn’t take consumers’ side and cripple technology’s golden goose.

So, once again, “caveat emptor” it is. Silicon Valley sees us as suckers. We’re on our own. Here are a few defenses available to you:

You can turn off “Location Services” on your iPad and iPhone. You can use your web browser’s tools to block tracking cookies, web-usage history, and ads.

When faced with a data form, only give the required data, and never give your Social Security number. On Facebook, minimize the personal data you post, and keep it private. Avoid giving locational data in your postings.

Each little bit of data seems harmless, but when they are aggregated, mined and sold, even harmless tidbits can be correlated into a disturbingly complete picture of you.

As long as the money machine hums, tech firms won’t be motivated to protect you or your data. Even your search for fun and friendship can be turned against you. To them, your identity is nothing more than a commodity.

So get smart about the technology you use. Don’t assume it’s safe out there.

(Tom Ehrich is a writer, church consultant and Episcopal priest based in New York. He is the author of “Just Wondering, Jesus” and founder of the Church Wellness Project. His website is http://www.morningwalkmedia.com. Follow Tom on Twitter (at)tomehrich.)