IT used to be that "anything you say can and will be used against you", but these days, anything you post can and may be used against you, too.
As social media sites continue to proliferate and with more people signing up, it has become easier to find out all there is to know about a person, even if he is a virtual stranger, in all senses of the word.
People often do not realise how much information about themselves they put up on social media, or do but assume they are protected by undecipherable passwords and security settings. Nothing put up on social media, however, can ever be truly private, no matter how ironclad the privacy settings.
If it's interesting enough, a status update, photo or tweet can be shared and spread exponentially as swiftly as it does for the haze to return to our shores.
A 2012 video from Belgium proved that learning a person's deepest secrets and even just mundane information such as his favourite colour or best friend's name is only a few clicks away, thanks to the Internet and social media.
Nowhere is this unsettling capability of social media -- to build a profile or digital composite of a person -- demonstrated more clearly than in the case of missing Malaysia Airlines flight MH370, where the global media has scoured the Internet to mine and cull whatever information they can get about the pilot, Captain Zaharie Ahmad Shah, and his young co-pilot, Fariq Abdul Hamid, to satiate the curiosity of readers.
The media and, in fact, everyone else, is using the digital footprints left behind by the captain, his first officer, and their nearest and dearest to build a profile of their personalities. What's unfortunate is that these need not be an accurate depiction of them.
"Sometimes, the person who seems to be at every party on Facebook is really a quiet person. We present a certain aspect of who we are to different people," said David Lian, general manager of a global social communications agency.
From Facebook and YouTube alone, gawkers around the globe now know that Zaharie is an avid chef who can cook butter prawns and beehoon noodles, loved remote-controlled planes, and had a flight simulator set up in his home.
From his video guides on a YouTube channel named "Zaharie Shah", people found out that he's an expert in waterproofing window panes, servicing air-conditioning units and repairing whirlpool icemakers. He's a big fan of videos posted by a user calling himself CrazyRussianHacker, a MacGyver of sorts, and watched videos about twisting balloons to make pirate swords, bears and cats.
From his "likes" and a T-shirt worn in a photo, it was surmised, unjustly, that he might have committed a heinous act as a form of protest against the government.
A foreign news report highlighted his Facebook photograph, which showed him holding a meat cleaver, suggesting perhaps that he's violent and bloodthirsty, when all he was doing was cooking dinner.
As for Fariq, we now know what his betrothed looks like, where she works, her position, and age. There are also those photos of him on the Internet with another pilot, and a pair of attention-seeking and grabbing blondes, one intent on making untimely claims.
Indeed, there is a treasure trove of information about a person that can be gleaned from the Internet.
In Facebook, for instance, "every time you like a product or even look at a page, the company itself is taking note", Katharine Knibbs wrote in Time.
This means Facebook ought not to be your private diary as what you do on the website "gets collected and catalogued", she cautioned.
It's very difficult to counter impressions and perceptions once they are formed. Worse still if you are not around to explain or give a true picture.
Are you aware how much your own digital footprint can reveal about you? What would you be typecast as? Pause before posting. Take stock of all the information and photos of you already on the Internet.
If that post or picture is something that may likely come back to haunt you one day, best refrain from hitting Enter.
Chok Suat Ling is New Sunday Times editor. NST Opinion Columnist 20/03/2014