Paul Johns of Complinet looks at how your online profile could ruin your travel plans, your career, and your life - should you be worried?

'I should warn people that the electronic footprint you leave on the Net will be used against you. It cannot be erased.'
- Andrew Feldmar, May 2007

When psychotherapist Andrew Feldmar was travelling to the US from Canada in the summer of 2006, he probably expected some stringent checks at the border. In the wake of 9/11, entering the United States has not been a trivial matter; foreign nationals are often kept waiting in line for over an hour while detailed questions, searches and background checks are carried out. Homeland security is a national priority, after all, and an insecure border poses an unacceptable threat.

What Feldmar wasn't expecting, though, was that one of those background checks would involve an internet search on his name. Among the search results was an article that Feldmar had written in 2001 for a psychiatric journal, relating his experiences in the 1960s with hallucinogenic drugs.

Despite having crossed the border more than 100 times since he'd stopped experimenting with drugs, Feldmar was told by a security guard that as a former drug user, he was no longer welcome in the United States. His fingerprints were taken, and he was turned back to Canada. In a subsequent interview with the International Herald Tribune, Feldmar said: 'I should warn people that the electronic footprint you leave on the net will be used against you. It cannot be erased.'

However, although it's true that Feldmar has no control over the fact that his 2001 article is freely available on the internet, and that this has had serious repercussions for his personal and professional life, what is not in doubt is that he wrote the article himself. More worrying are cases where similar decisions have been made using online information that is false.

A case in point is that of Taner Akçam, a Turkish-born visiting professor of history at the University of Minnesota. In February this year, Akçam flew from Minnesota to Montreal intending to deliver a lecture, but was instead detained for three hours at Pierre Elliott Trudeau Airport on suspicion of terrorism.

Akçam later told the Canadian Broadcasting Corporation that the 'evidence' for his being a terrorist turned out to consist solely of an entry about him in the editable online encyclopaedia Wikipedia, which he said was persistently vandalised by anonymous contributors who disagree with research findings that he has published.

These two cases highlight the increasing use of personal information that is freely available online to inform decisions that significantly affect people's lives. We're used to hearing about recruiters and human resources staff using online profiles on sites like MySpace and Facebook to vet job candidates before making recruitment decisions.

Many of us have secretively Googled for information about exes and potential dates. Now it seems that border police in both the US and Canada are free to use the same kinds of search to find information about travelers, and to use that information to decide whether a person should be allowed to cross the border.

But what if - as in Akçam's experience - that information is simply not true? One of the defining features of the Web 2.0 revolution is that anyone can publish information on the internet. Anyone can update a Wikipedia page, at any time, with any information they care to put there, true or not. The offending information may be removed later, but if it is there at the crucial moment when the subject is crossing a border, that person may suffer in consequence.

Similarly, anyone can create a MySpace profile or a Facebook page - in anyone's name - and populate it with whatever information they like. There is a vogue currently for creating spoof satirical blogs that are made to seem like the personal blog of a celebrity or other notable individual. The potential for online fakery is, in short, almost unlimited.

In the age of Web 2.0, people's online identities are so fluid and uncontrollable that they should not be relied upon - and especially not in isolation - to inform life-affecting decisions. And while I've used the example of border controls in this article, the same caveat applies to financial institutions.

Bank staff may be tempted to use free online searches for anti-money laundering (AML) or know your customer (KYC) checks, for example. But unless they corroborate the information they find online against official sources, perfectly reputable people may find themselves blacklisted, while others with a lower online profile but a more questionable background may pass undetected.

As Andrew Feldmar pointed out, almost everyone these days has an online footprint. But whether our footprint was made by our own feet is increasingly open to question.