FILE - In this Nov. 10, 2012, file photo, Notre Dame linebacker Manti Te'o waits for the snap during the second half of their NCAA college football game against Boston College in Boston. (AP Photo/Winslow Townson, File) (Winslow Townson/AP)

The details are still shaking out, but if there’s one tech lesson to draw from the strange story of Notre Dame football player Manti Te’o and his fake girlfriend, it’s that you are what you tweet.

Who you are online — on Facebook, Twitter, Pinterest and LinkedIn — has more or less become a central part of your public identity.

“We’re basically the sum of our offline and online parts,” said Sarah Downey, senior privacy strategist at the online privacy firm Abine. “And so many of us spend so much time online that they’re indistinguishable.”

Anyone watching Manti Te’o on Twitter would have sworn they almost knew Lennay Kekua, the girlfriend Te’o and Notre Dame now say never existed. As Deadspin reported, fans had seen the tweets between them, sent messages of support to Kekua’s “sister,” and saw Te’o mourn her death in September. They saw pictures of her, which appear to be taken from another woman’s Facebook account. And, as ESPN reported, Te’o may not be the only football player who believes he’s met Kekua.

The scale of the hoax is shocking but faking online personalities is nothing new. Celebrity parody accounts are everywhere. ‘Catfish,’ a movie and MTV show, centers on people who have fallen for the often fictional attributes of people they meet online. (It’s creator, Nev Schulman, told his Twitter followers that he’s getting to the bottom of Te’o case.)

There’s even, as the Associated Press reported, a Brazillian firm that will create a fake girlfriend for its customers. According to the firm’s Web site the company will post on clients’ sites a certain amount each week to convince friends of non-existent partners or inspire envy among one’s exes.

Michael Zammuto, president of the online reputation management firm, said that the Te’o situation offers a couple of lessons to those who are quick to trust a social network profile at face value. Those sites, he said, may seem to provide good information, but they don’t follow-up on what people say.

“Facebook and Twitter make no suggestion of validation,” he said. He said it’s much safer for hiring managers or even those smitten by an online profile to look for other sources, such as school alumni pages.

Finally, Zammuto said it always helps to take anything you read in profiles with a healthy amount of skepticism.

“Sometimes people who are pursuing [this kind of hoax] come up with fantastical backstories that are just too interesting,” he said.

In his statement on the matter, given to ESPN, Te’o said he will think twice before trusting people online. “In retrospect, I obviously should have been much more cautious,” he said. “If anything good comes of this, I hope it is that others will be far more guarded when they engage with people online than I was.”

Romance aside, Downey said that there are tips the average person can pick up from this extreme illustration of the impact social media has on your reputation.

To keep your own online persona in good form, Downey recommends a regimen that goes a little beyond conducting regular searches on your name.

In the course of her work, she’s seen clients’ reputations brought down by malicious blogs run by people with an ax to grind or because of an unfortunate search engine association with words like “arrest,” “pornography” or “scandal.” Searching for your name and terms like these — as well as setting up alerts about when your own name appears online — gives you a general sketch of what your reputation is.

And linking your profiles on different sites together, she said, is also a good way to create a net of search-engine friendly sites that will rise to the top of search results.

Finally users should take care to lock down the privacy of photos they don’t want popping up in unexpected places, whether it’s on a mysterious Twitter account or out of context on a job recruiter’s screen.

“The reality is anything that’s online can be used against you as easily as it can be used to create you,” Downey said.

Related stories:

Death of Notre Dame football star’s girlfriend apparently was a hoax

Manti Te’o: Dead girlfriend story is a hoax

Manti Te’o: NFL player says he met girlfriend

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