The lesson from Sony hacking scandal, be careful who you bad-mouth via your email
Like most people, I gave up watching Big Brother shortly after the 2004-6 golden age, but one catchphrase does stick in the brain: "If I've got something to say, I'll say it to your face, yeah?"
Variations on that sentiment became a sort of mantra for reality TV contestants. In a show where every action was subject to 24-hour surveillance, the most celebrated quality was not kindness or tact but blunt honesty, regardless of what trouble it might cause.
In confidential contexts (or at least contexts we believe to be confidential), the code of behaviour is quite different, as demonstrated by the Sony hacking scandal.
Leaked email threads from the accounts of Sony employees offered several examples of the nasty things people will write about a colleague but never dare to say to their face.
Angelina Jolie was branded a "minimally talented spoiled brat"; comedian Kevin Hart was called a "whore" for requesting more money, and screenwriter Aaron Sorkin claimed haughtily that he'd never heard of Oscar-nominated actor Michael Fassbender.
The language might be more colourful and the names more famous, but such communications are hardly exclusive to Hollywood. Lots of people have written or said things in private that they wouldn't want made public.
That's because talking smack behind people's backs has its uses - especially in a professional setting.
It allows people to vent their momentary frustrations without wasting time on pointless confrontation.
It helps foster solidarity among colleagues through the creation of a shared enemy.
Most importantly, it allows space for people to be people - at their nasty, petty worst - without unnecessarily hurting the feelings of others.
A bit of bad-mouthing behind closed doors never did anyone any harm, but we made a mistake when we thought that an email password would protect our privacy.
So maybe just nip out for a coffee instead?
• Ghostwriters don't do it for the riches and they certainly don't do it for the fame; Siobhan Curham, the novelist widely supposed to have ghostwritten vlogger Zoella's smash-hit debut Girl Online, was reluctantly outed last week, but insisted that she "did not invite any of this attention". So let's speak instead of a different celebrity ghostwriter, Rebecca Farnworth, who died of cancer last month aged just 49.
Farnworth is the woman who really deserves credit for Penguin's payday.
In 2004 she worked on Being Jordan, the first instalment of Katie Price's autobiography, which surprised the sceptical publishing industry by selling in excess of a million copies.
Four more autobiographies and nine novels followed - all bearing Price's name and all successful, but it was Farnworth's words that paved the way for the celebrity memoir money-spinner.
Price would then do her bit by turning up to book signings dressed as paparazzi bait. Good old Pricey.
Price was also always fairly open about Farnworth's contribution, telling a Radio 4 interviewer in 2012: "She's just amazing."
Novelist Martin Amis was another fan, declaring himself "impressed" by the volumes of Price's memoirs he'd read "as research": "They have the merits of candour and I would say a sort of honesty."
Honesty of that sort now belongs to a bygone age, so it's fitting that her death came just days before Katie Price revealed the dramatic results of breast-reduction surgery.
It's the end of an era for bold, brash and brassy teen role models and the start of a new one - the anodyne Age of Zoella.