There will probably be something like a "reasonable person" test for obscenity. However, there is pornography that depicts rape without being actual rape. If the intention is to ban fetish porn, then it is a clear violation of freedom of speech. Whether that is constitutional in Britain is beyond me, since they seem to be much less absolute about free speech than in the U.S., but clearly have some protections as well.
In the U.S., there was a recent Supreme Court decision [1] throwing out a law intended to ban crush porn, in which a woman crushes a small animal to death with her feet. They ruled that it was over-broad and could outlaw, for instance, hunting videos. A new law was passed immediately after the decision that had more specific language, and it has not, to my knowledge, been tested in court yet. Meanwhile, the court has upheld bans on child porn.
It seems to me that there is no need to ban possession of images depicting actions that are already illegal, but courts seem to think it's OK in the U.S.
In the U.S., there was a recent Supreme Court decision [1] throwing out a law intended to ban crush porn, in which a woman crushes a small animal to death with her feet. They ruled that it was over-broad and could outlaw, for instance, hunting videos. A new law was passed immediately after the decision that had more specific language, and it has not, to my knowledge, been tested in court yet. Meanwhile, the court has upheld bans on child porn.
It seems to me that there is no need to ban possession of images depicting actions that are already illegal, but courts seem to think it's OK in the U.S.
[1] http://en.wikipedia.org/wiki/United_States_v._Stevens