What not to do online

>POST INAPPROPRIATE PHOTOS It doesn't have to be full-frontal nudity to be inappropriate, but still so many people think that a snap taken on a drunken night out will take to Facebook like a duck to water. But instead of water, the duck dives beak-first into a vat of oven-ready orange sauce.

>ANNOUNCING YOUR UPCOMING HOLIDAYS It never ceases to amaze why people announce their holiday plans on Facebook or Twitter. "No work for two weeks! Dubai here we come!", may as well read "I have some valuables in my house that will be unattended for the next fortnight! Please help yourselves!"

>HAVING THOUSANDS OF FRIENDS No one should have thousands of friends on a site like Facebook unless they are running some sort of fanclub or an anti-Fianna Fail petition. Having thousands of friends is just poor quality control. Stop showing off and have a cull.

> BITCHING ABOUT WORK Your boss may not have direct access to your online profile, but they may have a colleague or friend who does, and it won't take long before the message to filter back. Recent history is littered with eejits who lost their jobs through imprudent cyber-ranting. From retail staff comparing customers to farmyard animals, to office staff posting crude effigies of employers, there is no excuse for this virtual faux pas. Giving out about work is what nights out with real people are for.

>BROADCASTING A PARTY We've all heard the one about the teenager who posted an invite to a party in his or her absent parents' house, only to find that everyone in the world and a random pervert turned up, the house burned down and a dog died. Announcing a party online is always a big mistake

>POSTING ANYTHING WHEN DRUNK Be it emailing an ex, changing your status to single after a boozy argument, posting up a sexy photo, or writing what you really think about your sister-in-law, don't do it after a few drinks. Dutch courage-fuelled online activities are like greasy kebabs at 4am; a good idea at the time, but will make you feel sick in the morning.

>AGGRANDISING TWEETING The concept of Twitter was short, spontaneous thoughts; the reality is people agonising over the 140 characters when all they wanted to say was that they had a disappointing sandwich. While it's all meant to look like it was off the cuff, and the top of their head, the result is the opposite.

It's the Ricky Gervais style of tweeting (whose humour is a one-trick pony that grew up to be a horse which he subsequently flogged to death), that clearly takes a huge amount of effort (and thesaurus use) to appear effortless.

>PERSONAL INFO People post their home addresses and phone numbers on social networking sites, in the naive belief that only their buddies will see them.

Software exists for the sole purpose of extracting personal information from anywhere possible and sell it on. Addresses and numbers are the jackpot.

If you're lucky it will just mean lots of calls from call centres trying to sell you IT services. If you're less so, see above.

Your friends have your number, if anyone else wants it, they can ask.

>EXTREME SPORTS

You may be dying to get online to post that bungee jump photo or black ski run shot, but more and more insurance companies are seeking out their customer's online profiles to see how much of a liability they might be. If they come across a photo of you waving a piece of bloody meat through a cage at a passing shark, you may find your premium goes up a little next year. I kid you not.