Facebook’s controversial decision to take down an iconic Vietnam war picture – which featured a naked girl – led the service to rethink its policies on nudity and art. But moderators have told us the new guidelines are confusing – and even Facebook accepts this is a grey area.

Paintings and other ‘handmade art’ that show naked bodies, and more graphic sexual imagery, are allowed. So is digital nudity. But ‘digital sexual activity’ has to be removed. Facebook concedes what is handmade, and what isn’t. Moderators need a keen eye - and common sense. This is its most up-to-date attempt to divine what is in good taste, and what is not.