As of today (5 April 2020) Zoom has made password and waiting room default settings. Two of my work colleagues have had unfortunate experiences (harrassment, showing porn, general disruption) on Zoom. Follow the instructions on the ADL site for extra security.

The Guardian carried this: https://www.theguardian.com/technology/2020/apr/02/zoom-technology-security-coronavirus-video-conferencing

Happy Zooming and hosting Death Cafes online - be prepared & be safe!