Right now, in some creative industries, Twitter functions as a sort of public address on the open web. With a name or a username, anyone can contact you—which means anyone can threaten you.

To reduce these threats, Twitter could increase its moderation of content posted to the site. But the kind of moderating that would be required to reduce these threats—and especially to reduce the kind of astroturfed, en masse harassment attacks employed by Gamergate—will entail hours upon hours of human labor. That work is financially and emotionally costly. The journalist Adrian Chen spent time at a moderating center in the Philippines and wrote about it this week for Wired. “From the moment you see the first image, you will change for good,” a therapist who works with online moderators told him. Any mass-moderation scheme would increase the number of people who would see these images for good.

So Gamergate is an existential crisis for Twitter. (My colleague Adrienne LaFrance identified a different kind of existential crisis for the service—a loss of vibrancy—back in April.) If the current lack of moderation continues, some high-profile users will give up and log out, and their friends and fans will eventually follow. But all this is a further crisis for a type of online life, one where users are publicly findable and accessible.