The world got a dose of social media etiquette from Mark Zuckerberg’s older sister, Randi, this week with the release of her new book Dot Complicated: Untangling Our Complicated Lives.

And despite being related to the Facebook (FB) founder, that doesn’t mean she’s  immune to social media gaffes. After posting a picture of her family last year at Christmas on Facebook she got upset when it was later re-posted on Twitter (TWTR).  To show her frustration, she tweeted:  “Digital etiquette: always ask permission before posting a friend’s photo publicly. It’s not about privacy settings, it’s about human decency.”

Social media has blurred the lines to what is appropriate when it comes to sharing, over-sharing and interacting with friends, family and coworkers online, but etiquette experts warn it’s user’s beware.

“We have to assume, even among our closest family, that anything we post on social media can be reposted,” says Diane Gottsman, owner of the Protocol School of Texas. “Not because [the re-poster] is doing it in a contrarian way, but they may want to share it with a friend, who then shares that with their whole network. Anything that is within a private domain may be retweeted or reposted.”

Ahead of the holiday season, which is peppered with work, social and family gatherings, here are a few dos and don’ts for your social media account:

DO: Connect with friends and family online. Social media can help to update and re-connect with friends and family during the holiday season you may not have had time to chat with throughout the year, Gottsman says. “It’s a great way to share family photos and greetings with people you wouldn’t normally share holiday greetings with [via mail].”

DON’T: Be overly political or religious online. No one wants to be inundated with political or religious postings during the holidays--or anytime, for that matter, Gottsman says. “We don’t need a step-by-step account of your holiday,” she says. “Share holiday updates without getting too political or religious.”

Jacqueline Whitmore, founder of EtiquetteExpert.com, also recommends avoiding rants during the holiday season. “That is a fast way to get deleted,” she says.

DO: Be cautious of leaving people out. The holiday season is full of parties and social gatherings, and posting photos and status updates of the festivities could leave some of your followers with bruised egos, warns Gottsman.

“People may ask, ‘why wasn’t I invited?’” she says. “There is always the chance of offending people.”

DON’T: Post photos of your boss or coworkers without permission.  Be sure you ask colleagues, and especially your higher-ups, before sharing photos of them on the web, says Gottsman.

“You always need to ask permission, especially at the office party,” she says. “And be sure not to post pictures of your boss in what may appear to be a compromising position.”

DO: Be mindful of security settings. Facebook, Twitter and other social media sites are often updating their privacy settings, says Whitmore, so be aware of any changes made as you share.

“These things change rapidly and you may not be sure if your posts are secure, so regularly check your settings,” she says.

Follow Kate Rogers on Twitter at @KateRogersNews