Your mom taught you how to behave at the table, to mind your Ps and Qs, not to hurt people’s feelings and to think twice before you say something.

Why then do these rules often fly out of the window when it comes to the world of social media?

Barely a month goes by without someone being in some of kind of trouble for posting something others deem rude, offensive, in bad taste or invasive.

So what’s acceptable and what’s not? What are the legal pitfalls? We asked experts to help us navigate the ever expanding digital obstacle course.

TAGGING

It’s best to ask permission before tagging anyone in a picture, says Daniel Post Senning, author of Emily Post’s Manners in a Digital World: Living Well Online. “Because when you tag, you’re publicly exposing them in some way,” he explains. There are two things you can do about unwanted tagging, says Lauren Dallas, social media guru and founder of business strategy company Growth Academy. One, you can remove the tag, and two, you can activate your privacy settings on Facebook so you can review anything you’ve been tagged in before it goes on your profile. Go to Settings > Timeline and tagging > Review, and enable “Review posts you’re tagged in”.

Should you be concerned about offending the poster by removing the tag? “Absolutely not,” Dallas says. “It’s your prerogative to remove tags you find unflattering or inappropriate.” According to South African law you also have the right to ask the poster to remove a picture you find offensive or damaging, says Carla de Beer of The Digital Law Company. “And if they don’t, they could be charged with defamation.”

WHEN IT COMES TO KIDS

Never post pictures of other people’s children without asking the parents’ permission, says Carla de Beer of the Digital Law Company. Also ask them if you may name the kids or tag the parents. “If it’s a group photo and some parents don’t want the photo posted and some do, pixelate or blur the faces of the kids whose folks don’t want them online,” she adds. There are free, easy-to-use apps you can download to your phone to help you do so, such as Blur Face on Android and Blur Photos on iOS. If you feel someone has violated the privacy of your child on Facebook, you can report the incident by going to facebook.com/help > Privacy and safety > Reporting a Privacy Violation > I want to report a photo or video that violates the privacy of my child, and fill out the form.

Legally speaking, children have a common-law right to privacy, Emma Sadleir, co-founder of The Digital Law Company, told Living and Loving. “There are two defences for a breach of privacy. The first is consent. For example, when you sign a school contract you generally consent to the school using your child’s image for school marketing purposes, including on social media. “The second defence is if the invasion of privacy is in the public interest – for example, an older child committing an act of vandalism.”

GETTING EMOJI-NAL

Emojis help convey tone – something that often gets lost in digital communication – but be careful how you use them, etiquette expert Diane Gottsman says. She warns against using emojis in the following situations: when someone is conveying serious news, when you’re dealing with a conservative business or client, or when you’re not entirely certain what a particular emoji means. For one thing, emojis might look different depending on the device they’re seen on – and not everyone interprets them the same way.

When in doubt over an emoji it’s best to leave it out, especially when you’re chatting to someone you don’t want to risk offending. You can also look up “definitions” of emojis at emojipedia.org.

TOUCHY SUBJECTS

Posting anything about religion, race or politics is rarely a good idea. “You need to remember that when you publish something on social media you lose tone, emotion as well as control over your audience,” says Carla de Beer of the Digital Law Company. “Something that might seem appropriate or funny to you might not come across that way.” If someone finds your post offensive they can report it to the South African Human Rights Council – and you don’t have to look far to see the consequences of online actions. A few examples: Penny Sparrow was ordered to pay a hefty fine or spend two years in prison for racist remarks she posted in 2016. Martin Theunissen was ordered to do community service and go on a 12-month social media detox for his racist rant in 2016. And last year Adam Catzavelos’ post about a beach in Greece being free of black people led to him going into hiding – and it ruined his family’s business.

GROUP DYNAMICS

If you’re the one creating a WhatsApp chat group it’s not necessary to ask someone’s permission before adding them because that person can leave the group with relative ease, says Carla de Beer of the Digital Law Company. Only group admins (the person who created the group and those they’ve given admin permissions to) can add or delete people, but you can remove yourself by tapping on the group’s name at the top of the screen and scrolling down to “Exit group”.

“Once someone has left, don’t re-add them,” De Beer cautions. “They left for a reason and don’t want to be there.” If people start sending inappropriate  messages, photos or videos on the group, tell them you’re having none of it, De Beer says. “We usually suggest that you voice your concerns – something like ‘not in my name’ – then leave the group immediately.” It’s especially important to speak up if the comment is defamatory, racist or sexist. “If you don’t disassociate yourself from the content you’re just as guilty as the person who posted it and you become part of the chain of publication. We call it ‘stepping into the shoes of the publisher’.”

MAJOR NO-NOS

Whining “Nobody likes the complainer,” says Anna Post, author of Emily Post’s Etiquette. “Your friends don’t want their feed full of Debbie Downers. It’s annoying, tacky and, most of all, cringe-worthy.”

Sharing without checking Fake news and scams abound online, so check the source before you share a story or post, etiquette expert Diane Gottsman says. Do some extra digging to suss out the article’s legitimacy, such as visiting the publisher’s website. Look out for suspicious domain names that end in “.com.co”. Also check out the publisher’s “About us” page to gauge if the content is satirical.

Posting pictures of a friend’s wedding The bride and groom often include a “no pictures online please” rule on their invitation – but even if they don’t, don’t do it, Post advises. Wait for the couple to post theirs first so you don’t rain on their parade, and check with them to see if they’re okay about you posting too.

Nasty stuff Poor spelling and bad grammar are viewed as impolite and lazy, Post says. And think hard before you swear online. “If you wouldn’t say it in a room full of strangers, don’t type it.”