Since it's become such an awful movie weekend over the past few years.
I imagine every state has different rules about how full theaters cn be but I can't imagine 30%-50% isn't a problem in some of the bigger LA or NY theaters. I know a few screening rooms (even an edit bay or two) that will not be able to resume screenings since they're so small and there's no way to socially distance and have enough viewers to make it profitable.