“I’ve been in your Facebook!” Ellen DeGeneres proudly proclaims at the beginning of her talk show, explaining the premise of her next segment. The day before, DeGeneres searched through the Facebook pages of all her audience members—looking for the raunchiest, strangest, and most embarrassing photos, airing them on prime-time television for millions of people to see. DeGeneres reads a few names, and the select audience members amble onto the stage before DeGeneres makes the grand reveal: an incriminating photo—someone wearing less clothing than they ought to, or a regrettable picture from a party that everyone tried to forget. And after much nervous laughter and awkward jokes, the audience members run back to their seats, a free iPad in tow, as compensation for the embarrassment.

Everything someone leaves online, be it an embarrassing photo or a LinkedIn resume, comprises what’s called a “digital footprint,” something Upper School technology coordinator Chris White says can be both good and bad. “A is a representation of yourself, either professionally or personally online… People have problems when they blur those two.”

Unfortunately, in real life, free iPads aren’t given out every time an embarrassing Facebook photo is leaked. The consequences of a misused digital footprint can vary widely, senior Katherine Jones says. “One of the things that made me not get a Facebook for so long was that possible employers or colleges could do a search.” Jones continued, “and they’d ask themselves, ‘what is Katherine doing?’”

At times, even the actions of other people can compromise your own privacy.

Last year, a particularly creepy app was removed from the Apple store, by the name of “Girls Around Me.” The app integrated the user’s Facebook and Foursquare, and scanned for women in the user’s area who had recently used their Foursquare. The app then gave users full access to any select woman’s Facebook profile, displaying photos, as well as letting users send the woman a message should they so choose. While the app was in direct violation of Foursquare’s application programming interface, all of the information the app used was unrestricted and consensually provided by Facebook and Foursquare users. “Sometimes information can be taken without your knowledge if you do not educate yourself to understand how your information is being used and what you can do to prevent it,” White added.

But just as a digital footprint can be harmful, it can also be beneficial. “I got my Facebook out of necessity,” Jones said. “I use it for the messaging aspect, and checking on my friends—it’s an easier way to communicate with people.”

For school related usage, a Facebook can be helpful to work with others on a group project, when communication would normally be more difficult.

For professional usage, White contends, there’s more than meets the eye when it comes to Twitter. “I think most people don’t understand its power. For me, it’s the best professional tool I have. I’ve met people all over the world, who are experts in their field… Before Twitter, I’d have never had a chance to interact with [them].”

Ultimately, a digital footprint is all about choices. Misuse and abuse can lead to long-term consequences, and vigilant understanding can lead to professional benefits. But no matter what, be careful what you post, because Ellen DeGeneres just might be watching.