Alice: And in the meantime, rapists see the poster and reassure themselves that their victims should've been more careful...
This. Exactly.
Just once, I'd like to see a poster that says "Real men don't rape."
There have been campaigns like that. Remember the TV campaign (aimed at young people, I think) where the rapist/abuser was trapped behind a glass screen watching his actions?
And not long ago (last year sometime) I saw a poster in the toilets at a Surestart centre with an image of a group of women drinking (iirc), with something along the lines of 'She may be drunk but she doesn't deserve to be raped'.
Campaigns like that are out there, so it seems like someone is getting the message about targetting the person who is really to blame -- which is why it's so gutting that posters like the one linked are still being made.
One last point: a poster like the one linked will never prevent a single rape. Okay, let's say a women avoids a situation and doesn't get raped? Yay, good for her. Except that then the rapist will rape somebody else.
It's all very well arguing that it's about protecting yourself. It sounds right, it sounds sensible, but it's forgetting the very real fact that there is a nasty undercurrent of belief in our society that a women who is drunk or dressed/behaving in a provocative way deserves everything she fucking gets, and posters like the one linked just add to this.
It's not just the potential rapists that these posters target; it's the women themselves. How many women do you think have failed to report a rape because they felt somehow that they were to blame? Because they were drunk, because they'd been kissing him, because they led him on.
That message needs to change.