Hi Francis. I found out something that you might want to take a look at, since we used Zoom for the last Papyrus IC telecon. You might even want to share it with those who participated.
A couple of days ago it was discovered that Zoom on mac has a massive security issue: it installs a secret web server that lets other people add you to a video con without your authorization.
A fix has been released, but even if you uninstall the one you have, you will likely have to do some additional steps. See [1].
In short, what you need to do is:
1. Uninstall Zoom (I recommend AppCleaner [2] to remove all traces of an app)
2. Remove ZoomOpener from your startup items:
2.1. open "System Preferences…”
2.2. go to “Users & Groups”
2.3. select your user (if it’s and Administrator you may have to click on the lock on the bottom left and enter your password)
2.4. click on “Login Items”
2.5. select “ZoomOpener” if present
2.6. click [-] to remove
3. Open a Terminal and type:
lsof -i :19421
If it shows “ZoomOpene”, you have to kill the process and remove a hidden zoom folder:
cd
pkill ZoomOpener
rm -rf ~/.zoomus
Check if it was killed by typing again:
lsof -i :19421
If it still shows or you installed it as root, you may have to kill it with ’sudo’:
sudo pkill ZoomOpener
[1]
https://www.howtogeek.com/427964/how-to-see-if-zoom-is-running-a-secret-web-server-on-your-mac-and-remove-it/ 
