Since we launched Zoom as a campus platform on March 13, 2020, there have been 36,439 meetings conducted by our community. And 3 reports of ZoomBombing (so far). There may have been others, but we have only 3 reported cases at this time1.
We have spent much time and effort adjusting the configuration of our campus Zoom account to address security and privacy concerns. Default settings for meetings have been modified, making it more difficult (if not impossible) for intruders to barge into a meeting/class and ZoomBomb it.
— Read on darcynorman.net/2020/04/10/zooming/