Much of it has centered on the games industry and is associated with a grass-roots movement called “#GamerGate,” a term used by a group of people who are fighting against what they say are unfair portrayals of video game enthusiasts as anti-feminists and misogynists.

But, paradoxically, people associated with the movement have systematically targeted and attacked women online, including women like Ms. Wu and Anita Sarkeesian, a feminist cultural critic who focuses often on video games and game culture.

Even events attempting to discuss and curtail the harassment of women online and in the gaming community are targets. In October, planners of the South by Southwest conference canceled two events — “SavePoint: A Discussion on the Gaming Community” and “Level Up: Overcoming Harassment in Games” — citing threats of “on-site violence” related to the panels.

After an overwhelmingly negative reaction from the greater online community, conference planners returned with a plan for a daylong meeting at South by Southwest, one dedicated to addressing online harassment and featuring prominent members of the gaming community and employees at the tech companies that are caught in the middle of the online fighting.

At the summit’s 15 panel discussions in the Hyatt Regency Austin downtown, security guards checked attendants’ bags on the way into each room. A half-dozen police officers milled about in the hours before the events started, scanning the crowds for any potential problems. Each session was attended by a police officer who sat at the back of the ballroom surveying the crowd and looking for unattended bags.