"My life is not your porn," read one poster. "We should be able to live, not survive," declared another.

The women brandishing those signs in the center of Seoul, South Korea's capital, wore large sunglasses, baseball caps or broad-brimmed hats. The headgear and glasses serve partly to ward off the sun, but mainly to make the protesters unrecognizable to men who might be hostile to their cause: the fight against molka, videos that are filmed using cameras hidden in public toilets, school changing rooms or even women's homes, and then posted on the internet.

The cameras, disguised as clocks, pens or light bulbs, are bestsellers. Police register thousands of cases every year, but perpetrators are rarely caught and punished. The protesters believe that this is because officials do not take women's concerns seriously.

The women, who have turned out in the tens of thousands on several occasions since the spring and are planning their final protest of the year in late December, are the most visible part of a wave of activism against sexism in South Korea, where spycams in toilets are not the only problem vexing women.

Despite its material wealth, South Korea was ranked 118th out of 144 countries last year in the World Economic Forum's measure of equality between the sexes.

The average South Korean woman makes only two-thirds as much as the average man. Several cases have come to light recently in which companies deliberately and systematically discriminated against female job applicants, even though that is illegal. A group of male executives at KB Kookmin Bank, for instance, lowered women's scores and raised men's on a recruitment test to ensure more men were hired. The case wound up in court, but the executives received only suspended sentences; the bank was fined a mere $4,500.

Although young women are better educated on average than their male peers, many of them are pushed out of the workforce after having children, either for lack of good child care or because companies simply will not take them back.

In terms of appearance and behavior, women and men are held to wildly different standards. A news anchor caused a scandal earlier in the year when she chose to read the morning news wearing glasses, rather than contact lenses. Many firms, it subsequently emerged, had an informal ban on female employees wearing glasses. A YouTube star who used her makeup tutorial channel to announce that she was giving up makeup to join the "corset-free" movement, which challenges unrealistic beauty standards, received a torrent of online threats.

Abuse from actual or would-be romantic partners is rife. A survey by the city government in Seoul found that four-fifths of women had experienced controlling behavior, such as boyfriends telling them what to wear or whom they could meet. More than half had suffered unwanted sexual advances and nearly two-fifths outright violence. "Misogyny is still common sense in South Korea," said Yoon-Kim Ji-youngof Konkuk University in Seoul. "People do not accept that women are worth the same as men."

But women are increasingly challenging this conviction. It is not just the anti-spycam protests. Many are cropping their hair, crushing their eye shadow and throwing away their lipstick — and posting videos of their rebellion online. Emboldened by the global #MeToo movement, a string of prominent women have spoken out about experiences of abuse. Young South Korean women, long wary of using the term "feminist" in conversations with parents or boyfriends, are starting to make their voices heard.

Criminal complaints about sexual discrimination or assault remain vastly more likely to ruin the reputation and career of the victim rather than the perpetrator. A recent move by Seoul city hall to roll out daily anti-spycam checks of public toilets in the city may reassure some women (as well as keep bureaucrats busy). But it does not get to the root of the problem.

Many activists emphasize the importance of shared personal experience in strengthening the movement. Kim Han Ryeo-il, who set up a feminist cafe and bookshop in Seoul's Gangnam district last year, says she wanted to create the kind of place she wished had existed when she was a single mother in dire straits after a divorce years ago. Her cafe hosts weekly meetings for women to talk about feminism.

Yoon-Kim believes the individual focus of the movement is its strength. Bottom-up organization, via social media and word of mouth, makes it unintimidating and easy to join. She thinks the anti-spycam protests have drawn such crowds because they speak directly to women's daily experience. "If you cannot even be safe from intrusion in the bathroom or in your own home, then where are you safe?"

Yet the focus on personal experience may impede feminists from seeking alliances with other groups battling social conservatism, such as activists for gay rights, or indeed sympathetic heterosexual men. The organizers of the recent anti-spycam protests, for example, specified that only "biological" women should take part.

Yet such alliances may turn out to be critical politically. Speaking out about mistreatment is one thing; changing a culture is another.