The City of Boston will not tolerate the buying and selling of human beings.

That’s what Boston Mayor Martin Walsh said Tuesday at a conference on sex trafficking attended by scores of activists, law enforcement, judges, philanthropists and survivors of the booming sex industry.

“We are very serious in the city of Boston around this issue,’’ Walsh said at the meeting at the Hotel Commonwealth in Kenmore Square, hosted by the city and the nonprofit Cambridge-based group Demand Abolition that is working to eliminate sex trafficking by focusing in on those who buy sex.

The all-day meeting brought together the group focused on the illegal sex trade that victimizes tens of thousands of women and girls across the US each year. Swanee Hunt, former ambassador to Austria and president of the advocacy group Hunt Alternatives that created Demand Abolition, said that only changing the actions of men – through law enforcement and deterrents like “public shaming” -- will stop the highly lucrative and violent sex industry.

During the meeting, presenters talked about new technology to go after Johns who mostly find girls and women on the Internet. They also talked about pimps, many of whom come from the same troubled families as its female victims and who specialize in psychological as well as physical manipulation. Hunt said only through going after buyers will the toxic cycle be stopped.

The meeting comes five months after a New England Center for Investigative Reporting report found that despite a 2011 state  law meant to increase penalties for men who pay for sex, none of the state’s 11 district attorney’s offices could site a single case in which a defendant had faced even a minimum fine of $1,000.

There have been some reported improvements but yet still a long way to go. Cherie Jimenez, a survivor of the sex industry, gave one of the most poignant calls to stop the violence during the morning talks. Jimenez runs a Boston-based group called the EVA Center that helps women trying to escape the sex trade.

She said of the women she’s spoken with, nearly half had gotten into what is often called “the life” after leaving the foster care system and nearly a quarter had children placed back into the system. “There is this cycle we need to break,’’ she said.  “We can end one of the oldest human violations of our time.”