What do you get when you mix WH Smith – the largest UK distributor of "soft" porn – and a dozen peaceful political activists putting lads' mags into paper bags emblazoned with anti-sexist slogans? A grade one police alert apparently. Luckily for us, bemused police officers ended up agreeing with our actions and rebuking the store manager for overreacting to a perfectly legal protest. The action was part of Object's first Feminist Friday – a new form of national grassroots activism whose aim is to see lads' mags no longer sold as part of mainstream media but put on the top shelf and recognised as pornography.

This would be a small step towards tackling attitudes that contribute to discrimination and violence against women. Gradual mainstreaming of the pornography industries over the past three decades has led to images originating from porn becoming part of our daily lives. Walk into any newsagent and you will face an array of newspapers and magazines that sexualise women and girls in a way which has little equivalent for men or boys. This is mirrored online and on our television screens. Our culture has, in effect, become "pornified".

The result? Pornified culture sends out a disturbing message that women are always sexually available. It dehumanises women into a sum of body parts, reinforces valuing women primarily for their "sex appeal" and undermines healthy sexual relationships – as well as reducing men to macho stereotypes that many men actually reject. It also reinforces racism by promoting exclusionary ideals that objectify women according to their ethnicity and fail to represent the diversity of women in the UK. The End Violence Against Women campaign (EVAW) – the largest coalition of women's groups in the UK – argues that it provides a conducive context for violence against women (pdf). Obviously, the media is not the sole factor in all this. Violence against women is nothing new. However it is clear that our pornified culture, combined with 21st century media technologies, has amplified both the prevalence and impact of sexualised imagery.

A voluntary code of regulation for the media and retailers is not enough. Despite legislation that tackles racist materials in the press, we still have no equivalent for sexism and the media is left to regulate itself. This is why EVAW has repeatedly called for the Department of Culture, Media and Sport to be included as a part of an integrated governmental strategy to end violence against women, so that department is obliged take this issue seriously. The UN Committee to End All Forms of Discrimination Against Women has frequently highlighted the UK's lack of progress in this area.

We could take a leaf out of Spain's book. The country has begun to integrate gender equality into media regulation by providing incentives for the media and advertising industries to tackle gender stereotyping. It would be a start, but it's clear that both educational and legislative action is also needed. Until then Object will continue organising Feminist Fridays and reviving activism on this issue. Our next action is tonight – let's hope for no more 999 calls.