Tracy Chou launched the Twitter app Block Party in 2021 to help users escape targeted harassment campaigns that she—as an Asian American woman—knew from personal experience could ostracize vulnerable voices from the public conversation. But on Wednesday Block Party closed its doors, becoming the latest victim of soaring new bills imposed by a struggling Twitter under new owner Elon Musk.

Under Twitter’s former ownership, Chou struck a deal with the company for free access to data—a win-win arrangement that would allow Block Party to grow and provide Twitter with a valuable anti-harassment tool to which it didn’t have to devote expensive engineering time. ···