Cyber spies: Why one tweet could cost you a job

These days, job applicants don't just need a good CV – they need a clean bill of web health. Rhodri Marsden on cyber snooping by employers

The internet has brought about a head-on collision between our personal and professional lives. A neatly presented online CV outlining a calm approach to high-pressure situations might stand in stark contrast to a Flickr album featuring pictures of that person screaming at a police cordon during a protest march. A reputation for high-standards of written communication might be compromised by a sequence of misspelled, expletive-filled rants on Facebook.

Wary of being brought into disrepute by the online misdemeanours of its employees, many companies implement social media policies that punish transgressors with disciplinary action; indeed, it's reported that 8 per cent of companies have dismissed people for inappropriate online behaviour. But far less is heard about those whose applications for new jobs fail because of things they've left visibly strewn around the internet.

An American firm by the name of Social Intelligence is gaining a high profile in the USA following the launch of its web-based pre-employment screening service, and the subsequent green light given by an initially suspicious Federal Trade Commission. But the evidence suggests that the practice of digging dirt on the internet has quietly become endemic among employers; you might think that you're being judged on the information you send them, but it might be the things you choose not to reveal that end up denying you the post. And you may never find out the real reason.

Social Intelligence has stated that its activities have very precise boundaries. For each applicant it investigates, a 'deep trawl' is done through the last seven years of blog comments, forum contributions and even classified ads that might have been posted, along with any visible social media content. From that data, a dossier is compiled of specific material that could be seen as dishonourable – eg, examples of racist language, mentions of drug-taking, photos of a sexually explicit nature, or references to weapon usage or other violence.

Those who've failed the Social Intelligence test include one person who made an online enquiry about a possible source of the pain reliever Oxycontin; past dossiers have also included details of membership of borderline-racist Facebook groups such as 'This is America – I shouldn't have to press 1 for English'.

We can't pretend that background checks are a startling innovation. Recruitment and headhunting services base their decisions on more than just the positive information they're initially handed; referees might be asked for personal opinions, professional insights and any other potential leads that would help to build up a better picture of a candidate. Indeed, you could say that old-school recruitment processes such as employee referral schemes and family business connections also operate pre-employment filters, based on the potential candidate's personal link to the company in question.

But employers are increasingly aware of and keen to use the huge informational resource that social media serves up on a plate; all kind of information is in the public domain, and incredibly easy to find – particularly if the applicant has an unusual name. As the chief executive of Social Intelligence has said, with something of a corporate shrug, "All we assemble is what's publicly available on the internet today". Nothing underhand going on here, they say; the company believes that the information is out there to be evaluated.

Of course, the vast majority of people haven't uploaded pictures and text to establish a corpus of data that could be used to microscopically analyse their attitudes towards everything from immigration to giving money to charity; most people have done it because they've been encouraged to do so by online companies dangling the carrot of friendship. Finding people who share your interests, rather than putting off prospective employers who don't. But both are undoubtedly happening.

"This probably started around four years ago," says Chris Purdy, director of Greenfield, a specialist recruitment business based in Luxembourg. "The appearance of networks such as LinkedIn and Xing changed the methodology of how we headhunt; if we wanted a quick reference on a name we heard about, that became the first place to go. But we know that HR departments don't stop at LinkedIn."

One might wonder what level of unacceptable behaviour would cause those departments to rule someone out of the running, but it's clear that the more senior the role, the more scrutiny applicants will be subjected to. "Your online reputation is part of your professional reputation," says Purdy. "If, say, a man is going for a private banking post that puts him in charge of €200m portfolios, pictures of him wearing a thong at a stag do aren't going to go down well."

Few users of social media would emerge from close analysis without some kind of stain on their character. Swearing, sarcasm and stupidity are rampant; we're fallible human beings, after all, and these services are designed to capture every facet of our personality. With Social Intelligence trawling back over seven years of material, growing older and wiser doesn't count for a great deal, either; past indiscretions will come back to haunt us. Mat Honan, an employee of the gadget-guide website Gizmodo, subjected himself to a Social Intelligence check which he failed, thanks to passing references to cocaine and ketamine that he'd made on his blog. But was he being judged unfairly? After all, someone following a spoof BNP Twitter account that satirises racist attitudes could mistakenly be labelled a racist themselves, and a debauched post-party photo might have someone mistakenly tagged as being in it when they aren't. This isn't an exact science; your online bill of health is down to the skill and judgement of whoever's tasked with performing the diagnosis.

According to Angie Youels, who performs HR-related services for small start-up companies, the interest in digging for a bit of colour on a candidate is down to the increasingly unhelpful information that's made available via traditional sources. "Part of the reason this is happening, in my view, is because references are so uninformative. Candidates know that they can find out what's been said about them, so rather than give a reference, they tend to just give dates of employment. In the past they'd have given fuller details."

Bearing this in mind, the airbrushed, one-dimensional and characterless profiles presented on sites like LinkedIn almost feel like an invitation for more invasive, exploratory digging. But there's a danger in digging too far. Companies will become aware of facts that they're legally not allowed to ask as part of the normal screening process. Details of age, ethnicity or political views will inevitably surface – as might, say, a female candidate's pregnancy. Once this information is known, it can't be somehow forgotten. Social Intelligence is predictably keen to highlight the fact that its service keeps such information at arm's length from the companies themselves; Mat Honan's dossier, for example, had his face blacked out throughout so as not to reveal his race, while still detailing his past encounters with drugs.

"I think it would be terribly wrong for someone to be influenced by the fact that a candidate held, say, different political views to theirs," says Youels, "but that's the danger – that people will be rejected because of their stance on this or that." The answer, according to Alexandra Arnott, a director at Octopus, an IT recruitment specialist, is honesty and diligence. "We may become aware of private information or opinions of candidates that are not relevant to the role or recruitment process we're following," she says. "So we must adhere to a strict ethical code and use our judgement and experience to ensure that there is no discrimination."

The process of choosing someone to work for you has always and will always be based upon judgements. Someone might miss out because of a covering letter written in a state of anxiety, or a job interview performance that was less than sparkling because they were feeling unwell. Gut instinct comes into play, and it can't always be quantified. If you have two CVs for a post, one listing "eating granola and doing yoga" as an interest, and the other mentioning membership of Camra, that information will register; a job that involves lots of post-work socialising might suit the beer-drinker better – but the granola fan might be angry that they lost out on that basis. Yet that's life; workplaces are full of people who don't fit in perfectly with their colleagues, and it's not unreasonable to suggest that social media searches could give employers a better idea of how that person might slot in.

As Chris Purdy says, it's human nature to be drawn to people with similar views as your own. "Someone with liberal views isn't going to want to take on someone with strong right-wing views – or vice versa," he says. "Fortunately, most of us don't put objectionable stuff out there. I don't think it's as big an issue as it's made out to be."

So are the gasps of horror in the US surrounding Social Intelligence merely paranoia? And is this just another example of us feeling adrift in the sea of confusion caused by the social media phenomenon? It's possible that, in time, companies will find that the hours spent scouring the internet for personal information isn't that productive, and that filters that gauge personal inclinations might work better. Network Rail, for example, has a 'culture quiz' which tests applicants for its graduate and advance apprenticeship positions against the culture of the business; if they score badly, they will not be encouraged to apply. Then there are tests devised by companies like SHL, that assess how a candidate fits with the requirements of the role – ie, proactivity, attitudes towards change, ability to deal with stress; these might not only provide a better assessment than a glance at a Twitter account, but they also remove some of that potential bias.

"If you've got nothing to hide," say those who are unconcerned about privacy issues, "you've got nothing to fear." This clearly isn't true; the prospect of our online presences being misjudged means that we might have nothing to hide, but something to fear. One solution: monitor your social media profile actively, suppressing anything that might compromise you. Don't indulge in cross-dressing – even for fun – or be photographed next to a load of marijuana plants. This, of course, may showcase you as being incredibly dull, but perhaps it's better to be safe than sorry. Alternatively, we could wait for Generation Y – the group most at risk from all this – to assume the hiring and firing roles currently occupied by the baby boomers. Perhaps they'll show a greater tolerance of the errant but very human behaviour that's displayed online.