While this principle has suffered some erosion in the past two decades, the words of now-Fair Work Commission President Iain Ross in 1998 remain good law: "employers do not have an unfettered right to sit in judgment on the out of work behaviour of their employees. An employee is entitled to a private life."

Public servants are not so fortunate. It has long been recognised that public service employment has particular status and significance which justify more expansive regulation. Hence various provisions of the Australian Public Service Code of Conduct are expressed to apply "in connection with APS employment" or even "at all times". Clearly, these empower public sector agencies to regulate the out-of-hours conduct of public servants to an extent. However, the exact scope of that regulatory authority remains somewhat uncertain.

This is problematic because, in our experience, APS agencies tend to err on the side of over-reach. We have acted in many cases where the entirely private conduct of a public servant suddenly finds itself under the Code of Conduct spotlight. Agencies seem to think that "at all times" literally means 24 hours a day, 365 days a year.

This is not a peculiarly federal phenomenon, either. In late April, The Age reported on the case of Mike Davis, a Victorian public servant who had been threatened with sanctions for running a podcast in his own time. His agency claimed that Davis' podcasting might constitute a breach of the Victorian Code of Conduct and its outside employment policy. Davis ultimately resigned, unwilling to tolerate such a gross intrusion into his private life.

Fortunately for public servants, there are some green shoots from within the law. In the 2016 case of Starr v Department of Human Services, a Fair Work Commission member reinstated a Centrelink employee fired for anonymous online commentary. The decision was unusually strident:

I reject completely the proposition that the APS value in s.10(3) ("The APS respects all people...") is to be read, in conjunction with s.13(11)(a), as requiring all members of the APS to be "respectful" at all times outside of working hours, including in the expression of their attitude to the government of the day. It would require express and absolutely unambiguous language in the statute to justify the conclusion that such a gross intrusion into the non-working lives and rights of public servants was intended.

Another win for the position that "at all times" does not literally mean "at all times" came from an unlikely source: the federal government itself. In the case of Comcare v Banerji, involving a tweeting public servant, the Code's proper construction was at issue before the High Court. Intervening in the case, Western Australia proposed an expansive interpretation: "the words are emphatic in referring to 'all times'".

Worried about the constitutional implications of this stance, the federal Attorney-General proposed a narrower interpretation in written submissions. "The Commonwealth plainly does not suggest that the Code regulates conduct that is 'devoid of any connection whatsoever with employment'", the submissions offered, adding "'at all times' ... does not mean 'always and under any circumstances'".

These may be positive developments. But there is a limit to their impact. How many public servants are willing to take a stand on these issues? Many - perhaps most - will (entirely reasonably) accept agency directions telling them to limit any possible external involvement in causes, activities or issues. As the Banerji case showed, the High Court has little sympathy for public servants who want to speak up about political issues pertinent to the agency in which they are employed in their own time.

This is a shame. A vibrant, diverse public service should be able to comply with the strictures of the Code of Conduct at work and contribute to the community in manifold ways outside the office, unencumbered by expansive employer oversight.

Overly draconian application of conflict of interest and secondary employment policies, and the dreaded "at all times" clause, are a recipe for public servants shying away from being active members of the community they serve. Davis' podcast, Humans of Purpose, was set up to profile "inspiring and purpose-driven leaders from our local community". Surely we want more public servants to have such side projects, not less.

The case of McManus v Scott-Charlton, from 1996, contains lessons that remain salient today.

McManus involved a public servant who was disciplined after he sexually harassed a colleague out-of-hours. While Justice Paul Finn accepted that the conduct fell within the regulatory reach of the employee's agency, Finn was clearly worried about his judgment being applied more broadly (he even added: "I should emphasise that my comments are limited to co-employee sexual harassment").

Regrettably, this caveat has been overlooked and it seems that the proposition taken from McManus in the subsequent decades has been that the public sector can intrude into private lives of public servants. Absent exceptional circumstances (such as sexual harassment), that was not the lesson Finn was hoping to leave. Indeed, he noted:

I am mindful of the caution that should be exercised when any extension is made to the supervision allowed an employer over the private activities of an employee. It needs to be carefully contained and fully justified.

The expansion of public sector control over the out-of-hours conduct of public sector employees at state and federal level has been neither carefully contained nor fully justified.

The failure to heed Finn's warning bodes ill for public servants and our society at large.