https://techcrunch.com/2020/04/03/zoom-waiting-rooms-default/

Zoom is making some drastic changes to prevent rampant abuse as trolls attack publicly-shared video calls. Starting April 5th, it will require passwords to enter calls via Meeting ID, since these may be guessed or reused. Meanwhile, it will change virtual waiting rooms to be on by default so hosts have to manually admit attendees.

The changes could prevent “Zoombombing”, a term I coined two weeks ago to describe malicious actors entering Zoom calls and disrupting them by screensharing offensive imagery. New Zoombombing tactics have since emerged, like spamming the chat thread with terrible GIFs, using virtual backgrounds to spread hateful messages, or just screaming profanities and slurs.