Workplaces are banning their staff from accessing social media during working hours, and trying to prevent them making comments about their employer after hours.
Across Australia, only 91 businesses have sought to formally ban their staff from accessing Facebook, Twitter and other social media sites as part of a workplace agreement.
The first enterprise deals featuring such bans began appearing in 2010, and increased five-fold in 2011, Fair Work Australia agreement searches show.
The agreements potentially expose employees to disciplinary action if, during working time, they use social media, defined in most agreements as Facebook, Twitter, YouTube, MySpace and ''all other internet sites whose function provides for social networking''.
Two recent agreements, for the bus charter companies Westernport Roadlines and Sandringham Coaches in Melbourne, specifically warn employees that any comments made via social media that refer to their employment or personal life, on sites such as Facebook or Twitter, could result in disciplinary action, ''up to and including termination''.
''It is important that employees consider the impact their online activities may have on their employment,'' the agreements warn. ''Employees should exercise careful judgment before posting details about their employment or personal life.''
Another employer, CPC Audio, in its workplace agreement, has banned all social media use during working hours unless done at the direction of a manager. And it specifically bans any reference to the business by an employee on social media sites.
John Battams, the Queensland Council of Unions president, told the industrial relations news service Workplace Express last week that blanket bans by employers on using social media were ''over the top''.
Mr Battams warned that the bans could ultimately gag employees who had genuine concerns about workplace safety or bullying.
Kate Jenkins, a partner at Herbert Smith Freehills specialising in employment law, said there was a rising number of employers having to tackle workers making ''abusive comments about co-workers, threats, sexual remarks, racist remarks, often about managers'' on social media sites.
She said that many people did not understand their personal use of social media could cost them their job.
And Ms Jenkins said a place like a public Facebook page was not the appropriate place to complain about workplace problems.
''The idea of someone having a grievance and raising it … via social media to create a campaign to potentially seriously damage a [firm's] reputation - that is really in conflict with an employee's obligation to their employer,'' she said.
Ms Jenkins said that the recent case involving the MP Peter Slipper and James Ashby, which had featured texts and other forms of online communication, had shown how destructive the electronic trail could be for both employers and employees.
''Whatever people are flinging about, it is going to live forever. Which is why it's just all better if you don't write things down - don't text them, don't post them, just leave them,'' Ms Jenkins said.