Bookmarked Etherpad’s Video Conferencing security: What do we do differently to Zoom? – John McLear (mclear.co.uk)
That’s the honest truth about modern software, it’s vulnerable. It’s ALL vulnerable so you have a choice to use something that is honest about it’s vulnerabilities or hides behind the door of closed source providing an ignorance is bliss situation.

Some great information and food for thought, @johnmclear is not trying to sell the product. Relevant to @dgilmour’s link to creativecommons & #OER I don’t think this is the time to pivot tools, but one to keep in mind.