As the Guardian put it last week, after-work life is rapidly disappearing and being replaced by non-working life. But it remains to be seen if the increased transparency regarding people's private lives because of new media such as Twitter and Facebook will make employers more tolerant - or make employees better behaved.

'The business use case in Twitter is turning out to be very important,' Twitter co-founder Biz Stone said last week as the company announced the possibility of cross-posting tweets to the professional network LinkedIn.

But the Guardian pointed out that social media sites such as Twitter can be dangerous if workmates see them - and they can erode the line between work and social life.

Twitter is a micro-blogging site where users can post information about themselves in 140 characters or fewer. It is also useful for keeping track of people, celebrities, brands, news outlets or companies which you are 'following'. And it is a handy tool too for short bursts of conversation.

But think twice about tweeting that you hate your new job but are grateful for the fat pay cheque. And you may want to consider changing your job if you are a teacher but also want to express your sexuality.

Those people with a second, non- work-related Facebook account or Twitter identity can do a lot anonymously but they have to manage their identities, said the paper. A London Underground worker recently had to leave his job after rude comments he made to an elderly passenger were circulated on the Internet.

Most of the problems have nothing to do with new media but occur simply because people tend to forget their manners online, the Guardian said. As behaviour is very important in public and we all live public lives now, etiquette is making a comeback, it noted.

If your boss is nice, he may tell you that he is following you on Twitter. But don't forget that, these days, camera phones and Twitterers are everywhere, so you become a representative of your company wherever you go.

Some companies, however, are getting tired of workers spending time on Facebook when they should be working.

According to a survey by Internet security provider ScanSafe, employers are increasingly choosing to block access to popular social networking sites, the London Times reported last week.

An analysis of more than a billion Web requests processed by ScanSafe each month showed a 20 per cent increase in the number of customers blocking social networking sites in the last six months.

Currently, 76 per cent of companies are choosing to block social networking and it is now a more popular category to block than online shopping (52 per cent), weapons (75 per cent), alcohol (64 per cent), sports (51 per cent) and Web mail (58 per cent).

Mr Spencer Parker, ScanSafe's director of product management, was quoted as saying: 'When Web filtering first became an option for companies, we generally saw them block access to typical categories such as pornography, illegal activities and hate and discrimination. In recent months, employers are obviously wising up to the dangers and negative impact on productivity linked to certain sites.'

If your company allows you access to Twitter or Facebook, here is some advice that applies to all forms of social media, and not just Twitter:

• Do not be rude. Do not be abusive about people, projects or your company. You may feel that you can talk behind someone's back to your friends and he will never find out - but it is becoming increasingly likely that he will.
• Do not post rumours or reveal things about colleagues, partners, projects or your own job situation. Even though private is the new public, some things are better left private.
• Do not post if you are in a bad mood or too busy. Post at haste, repent at leisure - it is easy to write something in the heat of the moment that you will come to regret, so wait until you have calmed down.

This article was first published in The Straits Times.