My company's policy for acceptable use of IT systems contains the following clause.

"[Company Name] respects Users right to a private life. However, [Company Name] must also ensure that confidentiality and its reputation are protected. [Company Name] therefore requires Users using social networking sites outside working hours on their own systems to refrain from identifying themselves as working for [Company Name]."

Are they within their rights to require me to do that?

yup, gross misconduct if you bring the company into disrepute. Civil liberties is a bit of a pisstake though

I'd say yes
but I'm not sure they could do much about it

Don't see why not. They don't want your (late night, maybe not properly thought out) opinions being interpreted as company policy

it would be bringing the company into disrepute if you posted that you routinely cheated your customers, but not if you posted a picture of your bottom. However, if it were true that would be a legitimate defence.

windowshopper in the pub later

"So who do you work for?"
"I'm sorry; if I told you I'd have to kill you."

seems all a bit much for a job at McDonalds!

Don't see why not. They don't want your (late night, maybe not properly thought out) opinions being interpreted as company policy

Fair point, but perhaps a disclaimer on Facebook could cover that.

JonT, I'm privy to official secrets but wouldn't kill you just for knowing where I work (which isn't McDonalds Spanishbarry).

yup, gross misconduct if you bring the company into disrepute.

That's the sad thing for me. The policy seems to assume staff are liable to bad-mouth the company or embarrass it in some way. Many colleagues are on there – most of whom are quite proud of the company and their work – and post nothing company-related anyway.

i like that that they "respect your right to a private life"

You seem to be slagging it off here.

Only outside working hours, on your own systems, though.

Log on at work, add your employer to your Facebook account – just make sure you delete it again at the end of the day. 🙂

You can slag em off as much as you like and imply who you work for, as long as you don't actually name them you're Ok right?

Seems fair enough to me, it's all subject to interpretation.

In my own job I have to be carefull what I do as and say as I have quite a public facing role and people's opinions of me can colour the organisation which I represent.

I had to ask some friends on "myface" to take down pics and tags of me from a few private events to avoid my private life bcoming public life and therefore compromising the integrity of my position.

I'm sure a good few politicinas enjoy some nob gags in private but they wouldn't want them quoted in the paper or used as election promises lest we all chnage our opinion of them (possibly for the better, but there you go…)