Recently I was linked to duelling articles on the topic of women saying "I have a boyfriend" to convince a man that is hitting on them to go away. The first one talks about how women shouldn't do this because it supports the idea that the only reason a man should leave a woman alone is because she is already 'taken'. (I would also add that it supports the idea that monogamy is universal.) The second attacks that idea and suggests that women should say whatever they want to get men to go away and that their need to escape men is more important than their need to help forward feminist goals in general.
I like the first article more instinctively but I recognize that it has serious problems. I think we really want to live in a world where a simple "I am not interested" is enough to convince others to go away without anything else being required. There should be no need for the subtle threat of male intervention nor the reliance on ubiquitous monogamous contracts to get people to leave others alone. If people in general try to rely on lack of interest as their leverage it will forward those goals.
When we tell people they aren't allowed to say certain things to get themselves out of situations they do not wish to be in we aren't forwarding feminist goals, we are pushing them back. Telling women how they must respond when being the subject of unwanted attention isn't making things better, it is just a new and different kind of oppression. What we need to acknowledge is that it is really helpful to find something to say other than "I have a boyfriend" when you can. This is similar to the way in which it is helpful for all gay folks when other gay folks come out. The more people that do it the easier it is for the next person to do it and that incremental change is how things get better. Nobody should be forced to be out if it is dangerous to them but everyone should be encouraged to be out if they can.
What really confuses me though is this world that so many of the women writing about this live in. They live in a world where they regularly go to businesses where they are constantly harassed, physically assaulted, stalked, and verbally abused. This is so far outside of my experience I don't even know what to make of it. There are reasons, obviously: I am a big dude, I go to bars rarely and when I do go I go with groups, and I go to more pubby bars than dance clubs. Add to that bars are expensive, noisy, and claustrophobically crowded. When you add all the heinous crap these women regularly experience I can't fathom what could possibly be at a bar that would make it worth all of that.
I am not saying that they shouldn't go to bars because they should do what they like and should feel safe doing so. What I am saying is that I can't for the life of me figure out what about bars has such appeal that it makes dealing with all that shit worthwhile.