Facebook is working to address a new privacy issue even as this story is being typed.

Early today, mid-afternoon in the UK and while much of the rest of the world was asleep, a story got onto the TechCrunch blog about a new bug. It seems that the chat function, which uses the privacy settings, enabled onlookers not only to see whether you were online, but to observe any other chats you were having and who had applied to friend you.

This is of course crazy. Facebook, to its credit, took the chat function down and it could well be that by the time you read this it'll be back up there with its usual reliability duly restored.

It's unfortunate that this should have hit Facebook in particular, a company that already had controversies stacking up over its privacy policy. But it does underline one thing: that Facebook, like any other social network, is still a very new company, and people relying on it to build their marketing efforts and some sort of social networking plan are backing one hell of a new horse.