Social networking sites such as Twitter have been making headlines in the wider media over the past week or so. Contrary to some initial reports, it seems that Manchester Utd has not banned its players from using such sites, but it has made it clear that it is unacceptable for players to disclose sensitive club information via such channels - no doubt the unfortunate example set by Liverpool's Ryan Babel, with his Twitter-based complaints about being dropped from the squad, provided a salutary lesson. And accorrding to the BBC, Councillors in Cornwall are also facing potential disciplinary action for improper Twitter use during council meetings.

What's this got to do with print? Well, this week I also heard on the grapevine about a pretty senior print employee who has been given their marching orders for posting inappropriate comments about a colleague on a social networking site. In another incident, one person's status update resulted in a long comment trail of work-based moans that reflect pretty poorly on the company referred to.

Why anyone would be so daft as to post career-limiting comments in such forums, I don't know. Never underestimate the power of stupid people in large groups, as the saying goes.

According to a recent survey of 450 companies by Careerbuilder.co.uk, 28% had sacked someone for comments made on social networking sites and I imagine that figure will only increase. Most companies now have clauses in their employment contracts relating to internet and email use, and those that don't should.

It would seem that some people would also benefit from a similar "common sense" clause to be hard-wired into their own heads, requiring them to engage their brains about the potential consequences before clicking post.