Computer science, like technology in general, is seen as a masculine field and the under-representation of women an intransigent problem. In this paper, we argue that the cultural belief in Australia that computer science is a domain for men results in many girls and women being chased away from that field as part of a border protection campaign by some males--secondary school teachers, boys and men playing games online and young men on campus at university. We draw on American feminist philosopher, Iris Marion Young's analysis of the "five faces" of oppression to suggest strategies whereby Australian universities could support women in computer science and educate men about respectful behaviour and gender equity.