The founder of Zoom apologized for privacy feature flaws and so-called “Zoom-bombings” that have taken place as the video conferencing company’s popularity has skyrocketed during the coronavirus crisis.

With its free app downloaded more than any other in the United States and dozens of other countries in recent weeks, Zoom stock shares doubled since the start of the year as workers are stuck at home under widespread stay-at-home orders meant to stem the spread of the COVID-19 virus. As Zoom usage has risen — there have been spikes of up to 200 million people per day in March, up from 10 million in late December — so has law enforcement concern about the remote meetings being hacked and users being harassed or exploited.