Guidelines to keep the Group Chats as secure as possible

When setting up the group chat make sure you follow these rules to keep it as secure as possible

Make sure that you add a group description, so everyone knows why they have been added to the group.
In the description of the chat include a URL link to any relevant information including your group agreement and any rules for the chat.
In settings, turn off the group link (there is no group link in WhatsApp)
Make sure that only admins can add members or access the invite link.
Make at least three trusted people admins including yourself.
If actions are happening soon, make sure you set disappearing messages to a day or a week. Otherwise 4 weeks should be fine (Only Signal can do this automatically however Admins in Mattermost, WhatsApp and Telegram can delete others' messages.)

Security on chats

Ideally only add people that you know well or are verified by others (trusted rebels)
If you are doing spicy actions make sure people use pseudonyms and burner phones if possible, and that those are added to the correct chats (~~Normal~~with their normal names and numbers removed).
Make sure there are separate secure chats for action days or spicy actions so that you can delete them afterwards.
Make sure only admins can add new members to the chat.
Make sure you set disappearing messages.
Make sure you keep the group links off.
Remember that many chat platforms attach media and files and links separately, so admins should regularly check that old media files and links are deleted
After the chat is done, and everyone has agreed that the group chat is done with, leave the group and delete the chat off your phone
Some members may not do this, so once the chat is done with, admins can remove members individually and then delete the chat off phones by deleting the group chat altogether - in this way people are not on lots of different chats that have ended which may cause security issues should someone’s phone be seized.