You have to wonder about some people. Take Julie Tyler, 27, of Dunedin.
Tyler currently works for Burger King and decided to slag off her employer on Facebook.
"Real jobs don't underpay and overwork like BK does," she said on a friend's Facebook page.
Apparently, her comments were posted on a "private" section of Facebook, not open to all, but a colleague reported them to management.
Tyler faced the sack, but following union involvement, she received a final written warning, which the union still plans to appeal against.
Burger King sees the matter as Tyler bringing the company into disrepute, but for the union it is a matter of free speech, likening her comments to pub chatter with friends.
Tyler is probably right in her comments about fast food work, but if you publicly abuse your employer, it is inevitable they will lose faith and trust in you. And the trouble with online comments is that they are permanent, accessible and "public" for others to see.
Not only do many businesses use Facebook themselves, they may also monitor the Facebook use of their staff, and they can also use tracking software to monitor what is said about them on social media and other sites.
Indeed, media experts have long warned that a posting on Facebook or other social-networking site is like putting something on a public notice board. And this applies to us all, not just the famous.
This month, for example, radical Maori Party MP Hone Harawira was disciplined by his party for calling his colleagues "dickheads" on Facebook, amid other misdemeanours.
It certainly seems that it's time to be more careful about what we say online, with some companies having more draconian policies than others. Commonwealth Bank, for example, is reportedly considering changes to its social media policy after it was discovered that employees could be fired for talking about the company on the site.