What counts as intrusion?

There are no pictures of Kate Middleton topless on Glopho. Nor Prince Harry in a Vegas hotel room.

Obviously they are both members of the British Royal Family, and they have both recently been photographed in a state of undress. And in both cases those pictures have been published, albeit in the case of the topless Kate pictures only in France, despite the protests of the Royal Family.

And yet the two incidents are very different.

One was taken during a drunken party on a camera-phone - with what appears to be the tacit approval of those pictured - and the other stolen without the subject's knowledge.

Prince Harry's naivety in inviting a bunch of party-goers he barely knew into his luxury hotel suite, without imposing or controlling their use of cameras, is largely seen as foolhardy. He was a young man, behaving like a young man might, enjoying a holiday before returning to work in a war-zone. This was a soldier's life. This was a young man having fun, and the pictures of his high jinx barely caused a ripple once they were published.

The photos of Kate Middleton topless on a sun-drenched balcony are a very different matter. The royal couple had every reason to believe they were in private. They had not invited the photographer into their world. Indeed given the distance these images were taken from - and judging by the quality it would be safe to presume hundreds of metres was likely - it is reasonable that this was a well planned operation of a seasoned paparazzi with an extremely long lens. These pictures were taken with a complete disregard for the couple's privacy that they had gone to pains to try and secure.

The proliferation of phones with cameras has made us all capable of capturing the news and with this new found power comes a whole new set of responsibilities and behaviours that we will all have to learn, on both sides of the lens. Perhaps though we shouldn't be looking to professionals like the photographer of Kate and Wills on holiday, for guidance.