Embarrassing photos on Facebook have hurt many careers, but recruiters now warn that the main internet site for business networking, LinkedIn, is increasingly being used to screen potential employees for what they do in their personal time.
LinkedIn will announce today that it has attracted 2 million Australian professionals and more than 100 million worldwide.
The website offers white-collar workers a respectable location to network and post their resumes for potential employers. The number of Australians on the site has doubled since last year.
Robertson Search partner Paul Rush said LinkedIn was very popular but carried tremendous danger.
"Recently we had a candidate that used LinkedIn in the same way he used Facebook," Mr Rush said.
"The hirer basically pulled the interview . . . because the social side was way over the top."
One danger is a growing trend of people connecting LinkedIn to Twitter accounts and other social networking sites. That increases the amount of information available to would-be employers and business contacts, creating the chance they will come across something too personal.
"It is a danger for executives looking to create a profile . . . because in Australia we're still relatively conservative compared to the US or UK," Mr Rush said.
Ambition Careers' managing director of the technology division, Andy Cross, said LinkedIn had become the most important networking site for professionals.
But he said the site's lack of auditing meant there could be exaggerations.
"Many people question how useful a recommendation can be, given they're usually written by friends and colleagues," Mr Cross said.
"My predecessor still lists herself as working in my job and I've had it for the past five years."
Examples of entirely bogus accounts also exist. "John Smith" the "Bank Robber" from Equatorial Guinea is just one example.
Another danger is joining controversial "groups" on the site which are then openly advertised on profiles.
Choices range from the legitimate to the controversial, such as "Social Media for Business is Crap" to others that complain about doing work.
But, faults aside, Mr Cross said LinkedIn generated more leads for business than Twitter or Facebook could.
"It is very useful for generating leads, and for people trying to identify new employees it can be mined quite well," he said.
LinkedIn's Australia and New Zealand managing director, Cliff Rosenberg, acknowledged the risks and said people should keep their social and business networks far apart on the internet.
"Facebook is very much aimed at family and friends," he said. "But our members are telling us they want to keep it far away from us.
"What you do on a weekend is often irrelevant to what you do in your professional life."
Mr Rosenberg, who recently opened a second Australian office in Melbourne, said the site's privacy and security options were designed to keep nosy employers away if needed.
"As with all tools out there, individuals really need to be responsible in how they use them," he said.