By now you've heard about Notre Dame star linebacker Mantai Te'o and his fabricated internet girlfriend. There are a lot of reasons and ways that this could have happened. Te'o claims that he was duped and not behind the accounts, but regardless of who is to blame, this was a deep, meticulously planned deception in many respects, and horribly slipshod in others.
So let's play a thought exercise. If you were going to fabricate a fake human on the internet, how would you do it?
Every photo taken by a modern camera—and yes, that includes your cell phone—contains Exchangeable Image File Format, or EXIF, data. This is metadata that will provide information about when, where, and how the photo was taken. It will typically contain data and time, as well as camera settings, and occasionally copyright info that can be used to determine what type of camera was used. EXIF can also contain geotagged information, which will display where the photo was taken using your phone or camera's GPS data.
You can remove the EXIF data in photoshop by simply loading the photo in, selecting Save for Web, and setting Metadata to None. There you go, all done: Any photo of her will be untraceable. That said, for anyone bothering to dig up dirt, the total lack of EXIF data on all your photos will be a HUGE red flag. It's a problem, but at least you can fall back on "I value my privacy," or some story like that.
This should be obvious, since word will always reach back to the original person, but it can be tempting because a real identity will stand up to more advanced vetting. They'll exist in registrars and in hospital records and government records. And if you simply refer to vague background details, and distance the social media accounts enough, it seems like it can work. But it just adds one more variable to what's already going to be a volatile house of cards. Any thorough inspection into either a real person's stolen identity or a made up one will probably crack your scheme, so there's no need to introduce another variable.
This is easier if family and friends are complicit in your fake identity, as you'll be able to create something resembling a real online history. Facebook's Timeline and photo backdating feature will help here, since you can edit any Timeline event or photo to appear as though it was posted at ANY TIME YOU CHOOSE. This is intended to be used for you to create a comprehensive life-long scrapbook, but it's just as easy (and more likely) to use it as a means to create a fake narrative—whether about being at some RAD concert, or being at a bar with some friends instead of cheating on your poor girlfriend who lives with you. Or if you're creating a person out of thin air.
You're on your own for Twitter and Instagram, though, so you'll probably want some lead time to flesh out those accounts. You'll need alibis to interact with them, and hopefully cross-post enough that it seems like your Canadian girlfriend actually has a life, and doesn't totally exist in a vacuum.
The first and easiest way to get caught making someone up is to use a photo that's available on the web—anywhere on the web. No matter how deep you dig, Google's web crawlers dig deeper. Anyone can upload an image or drop a link into Google Image Search and Mountain View's electronic hoards will search for similar-looking photos. It was one of the key ways that Te'o got busted.
So you're either going to need to rely on a cache of photos of a human that you know for a fact that have never been on the internet, or have a partner in crime to pose for them.
The surest way to retain plausible deniability is to never, ever claim to have met up. There's just no upside, unless you're trying to convince your high school friends that you've actually had sex with a girl from the next town over, in which case you can't really get around that. But for basically literally absolutely any other reason you might have to fake the existence of a human being, just don't do it, it's not worth it. It's the difference between having a chance to bail out and claim a "hacker" deceived you and having zero buffer on your gigantic, absurd lie.
This is sort of a double-reverse, but you want to put as much distance between the online, public identity and any kind of legitimate background check. To use Te'o's case, "Lennay Kay" was a decent front for "Lennay Kekua," and a reasonable thing a person might go by online. People use all kinds of pseudonyms to make themselves harder to search for, so why not your imaginary girlfriend? It's a perfect cover for making your fake human a pain in the ass to find.