As the COVID-19 pandemic drags on, many are desperate for gatherings—not just big events like concerts but even little ones, like in-person group conversations. Enter Clubhouse, whose app allows handfuls of people to gather in digital rooms to talk about anything from technology to art to politics. Since its April 2020 debut, it has lured more than 10 million weekly active users, including Elon Musk and Oprah; each had to be invited by an existing member, giving the app an alluring sense of exclusivity. As CEO Paul Davison takes Clubhouse mainstream, titans such as Facebook and ByteDance are reportedly rushing to launch copycat services. One problem to sort out first: moderation, as some rooms have been plagued by harassment and other issues.