@Can someone explain
> Xander: I'm confused. Does this law affect websites or users?
> Say I go on a forum and someone has posted "pornographic material that realistically depicts bestiality or necrophilia, rape and other non-consensual penetrative sexual activity, whether violent or otherwise". Am I in trouble for just having viewed the image?
The crime is "possession". Of course since you have visited the website, the image will be cached on your computer, so you are "in possession" of it, even if you didn't save it.
> Is the original poster in trouble for making the image?
Possibly, but only if they're in the UK.
> Is the person who made the image in trouble (even if the image is just a detailed drawing / photo collage)?
If it's "realistic".
> Clarification would be great :)
The Ministry of Justice is supposed to be providing "clarification" before this law comes into effect in January 2009, but I wouldn't hold your breath.
I wrote to Harry Cohen MP (the only Labour MP who seems to give a toss about objecting to this ridiculous law) with twenty questions for the MoJ. That was back in July, but so far there has been no reply from them.
See http://www.seenoevil.org.uk/phpBB2/viewtopic.php?t=803 for the letter.