Public servants have a ''special job'' and should be unsurprised if they are disciplined - even sacked - for criticising the government, an employment law specialist says.
Last week, the Federal Circuit Court rejected Michaela Banerji's application to prevent the Immigration Department from sacking her, after she had used an anonymous Twitter account to criticise Australia's refugee policies.
Ms Banerji had argued that any finding of misconduct against a public servant ''for expressing a political opinion contravenes the implied constitutional freedom of political communication''.
However, Judge Warwick Neville said past High Court cases showed that Australians' implied rights of political expression were limited and did not ''provide a licence … to breach a contract of employment''.
A Meyer Vandenberg Lawyers partner and government employment expert, Jennifer Wyborn, said the decision confirmed the well-established understanding that employers had some rights to dictate staff behaviour outside working hours.
She compared Ms Banerji's case with a high-profile workers' compensation case before the High Court, involving a public servant who was injured having sex in her motel room while on a work trip.
''They both explore the question: how far can your employer's tentacles extend to control your activities in the private sphere? And the answer is: a pretty long way.''
Ms Wyborn said social media such as Twitter and Facebook were a ''big challenge'' for federal government workplaces.
''Some departments have been very active in this area: developing policies, setting out what their staff can and can't do. And people often feel that this impinges on their personal freedom.
''But they need to remember that public service employment is a special arrangement and it differs from a normal employment contract.''
The Public Service Commission warns bureaucrats against making public comments that could be perceived as ''harsh or extreme'' criticisms of any politician or policy, even if they make the comments in an unofficial capacity.
The commission says public servants must also uphold the service's code of conduct and values, such as impartiality, ''even when material is posted anonymously''.
Social media expert Craig Thomler, who is the managing director of Delib Australia, said on Tuesday that anonymity was no protection for government staff.
''The only safe course of action for public servants using social media is to be very cautious of what they say,'' he said. ''Regardless of their intent, it could be interpreted in a way which could be [damaging].''
The Banerji decision was unsurprising but concerning, he said.
''There is a crackdown occurring in the [Australian Public Service] around people's use of social channels and I think that's a worrying development,'' he said.
''We could end up with the only people willing to work in the public service being those willing to be silenced.''