Looking after your friends is great. Telling a rape survivor's friends that they are partly to blame if their friend is raped is not OK.
Telling women that they are more vulnerable just because they are alone is not OK.
from the article I linked to:
"It’s not that we’re insufficiently aware of our own vulnerabilities; on the contrary, we’re all crushed by the constant reminders of how vulnerable we are. From early childhood we’re taught to be fearful of the wolf that lurks in the shadows. We’re reminded not to stray too far from the forest path or else we’ll get eaten up. We grow older, watching films and reading stories in which the rape and mutilation of women serve as common plot devices. We are told to think of ourselves as laptops, as unlocked doors, as open wallets, as property that anyone might take unless we’re locked safely away. We know we’re not meant to go outside. Outside might, statistically, be safer, but it doesn’t feel that way."
and
"Of course, it is not just women who will see posters such as this one. Rapists will, too. And what does this say to a rapist, if not “this is how things happen”? When women get drunk, when they meet strangers, when they wander off alone, this is how things work. Rape is what happens when women “make themselves vulnerable.” As Jill Filipovic points out, research has shown that “cultural opposition to rape myths makes men less likely to commit assault, and acceptance of those myths makes sexual assault more likely”:
In social groups where there is wide acceptance of rape myths – for example, the beliefs that acquaintance rape is a problem of communication or "mixed signals", that rapists simply can't control their sexual urges, that women often lie about rape, or that women invite rape upon themselves by their actions or manner of dressing – rape proclivity is higher. When men internalize rape myths, they are more likely to commit rape or see rape as more acceptable.
A woman can only make herself vulnerable if others have already learned to see her as potential prey."
Try to think beyond your 'women are just like children' Analogy...