WHAT is a private life in a digital world? That’s a question the courts are deciding. Every worker has a human right to a private life, but in a social-media age, where does your private life start and end?

Perhaps because platforms like Facebook and Twitter are relatively recent, the potential for social-media posts to wreak havoc with our reputations and careers is a lesson many people are still learning the hard way.

Many column inches have been dedicated to the politicians forced to explain a tweet sent 10 years ago, or to cyberbullying and fake news. Much less reported is the fact that careless use of a social-media account is a fast-growing way to lose your job.

In our new report for the IER, Social media and the law, we review recent case law to analyse the approach of the courts to workers claiming unfair dismissal after being sacked for their social-media activity.

There’s no new law to apply to these cases: existing unfair-dismissal, equality, confidentiality and human-rights legislation are called upon just as they would be if the incidents had occurred — as online slang would term it — IRL.

But some of the rulings may surprise you. The charity worker who left a comment on a potentially offensive Facebook post written by someone else was fairly dismissed, the court said. But the public figure whose Twitter account broadcast a picture of an unmentionable part of his anatomy to thousands of potentially young fans should keep his job.

So what are the deciding factors in such cases? As is often the case at tribunal, the Devil is in the detail. Mentioning your employer or place of employment on your profile or in your posts could negatively affect your employer’s reputation if you post something deemed offensive online — even if it has nothing to do with your job.

Meanwhile, a controversial view may be let slide if it is expressed in mild, rather than coarse or abusive, language. And workers and their unions should be aware that employers’ social-media policies — so long as workers know about them — will normally be upheld.

A key takeaway of our research is that there is no such thing as a private life online.

Social-media posts, and even emails, can be distributed endlessly, screen-shot, photographed, or copied and pasted. A glib comment made to 150 Facebook friends may not feel like a public statement, but as at least one case has shown, it can be treated as one in court. After all, that’s 150 people who could share your words with 150 more people and once it’s out, there’s no way to stop it from spreading — the internet never forgets.

The most troubling cases we came across were of employers deliberately looking for material online that they could use against their workers.

“Digging dirt” is, in our experience, an increasingly common practice, used to vet potential employees and, most disturbingly, to conveniently sack existing ones. While not all of these cases has worked out on behalf of the employer, some have.

It’s not always easy to protect a worker in these situations, although the worker’s claim can be strengthened if it can be shown that the employer was aware of the alleged breach of conduct at the time it occurred and “held off” on using it against them until it became convenient to do so.

So what of the future? Some of the recommendations we make in our report echo old problems that are now affecting social-media cases as well as more traditional unfair-dismissal claims.

The reliance of the law on the so-called “band of reasonable responses” — a test of proportionality that is entirely based on what the average employer considers fair — is clearly biased against workers.

There’s an easy fix to this issue, one that is laid out in the IER’s Manifesto for Labour Law — take into account what the average worker considers fair too. But we could go further and just throw out the “band of reasonable responses” altogether.

Bring back lay members at tribunals and let them make their own judgement as to whether a dismissal was reasonable or not. That’s the way it used to work and the old system had fewer issues than the one we have in place now.

Outside of legislative reform, there’s space for union action too. Concluding our report, we provide a practical checklist for unions to follow when protecting workers in cases involving social media.

We’d also urge unions to keep employers’ social-media policies on their radar. Are their stipulations realistic? Are the penalties fair? This is certainly an area that could be improved through negotiation.

Social media and the law is now available at a subsidised price for trade-union members at ier.org.uk and we’d encourage you to read the full report. But for now we’ll leave you with our overriding piece of advice — if you haven’t got anything nice to say, only say it IRL.

Paul Scholey and Daniel Kindell are Partners at Morrish Solicitors.