Fake bomb

BBC NEWS UK Fake bomb 'reaches castle area'

What's the chance of the Sun journalists being investigated or charged? Surely there's a whole bunch of things they could be charged with.

Let's see...The obvious one to me is trespass, but what else could the Palace and Police stretch to if they saw fit?

Threatening behaviour? They claimed to have a bomb, fake or otherwise. You could be done for carrying a fake firearm - can you be done for carrying a fake bomb?
Wasting police time? Indirectly I suppose, but a lot of time will be taken up with the Met's inquiry.
Obtaining a pecuniary advantage by deception? I'll bet they've sold a lot of papers off the back of this story.

Is there so little going on the world at the moment that the Sun feels the need to invent themselves a story? They need to try watching the news sometime...