The new timeline feature, which will activate automatically, will create each user's online life, posting old photos and status updates, for other Facebook users to view.

In a panic, many users have begun to delete old photos and updates so that other users can't see their former online lives.

Recruitment and training organisation MyGateway marketing manager Steve Wisbey says people must be careful when they use the website.

Mr Wisbey says he tells his friends not to "air their dirty laundry".

"I would say with any social media — ensure you would be happy with your mother reading it and seeing your photos and you will be fine," he said.

Mr Wisbey said employers used the website as a reference and that they Googled respective employees.

MyGateway human resources manager Veronique Besnard said the company had 300 staff under 21 years of age.

Ms Besnard said MyGateway recently developed a social media policy to provide its employees with guidance on what was acceptable.

She said MyGateway had launched a policy after several incidents on the social media site, including an employee posting a planking photo, that sparked its introduction.

"(MyGateway's employees) need to understand it's a permanent message that they're putting out there," she said.

"It could be detrimental in the long run."

She said MyGateway's social media policy ensured that its employees understood what was acceptable once they had became employees of MyGateway.

She said employers needed to be wary of discrimination too.

"All human resource people are aware that (social media) shouldn't be used as a traditional reference check," Ms Besnard said.

"It's not a tool that is recommended to human resources professionals."