U.S. vs. Thomas Caldwell (references Signal chats)

Per the document, Caldwell seems to have installed signal relatively recently (months rather than years) and might not be familiar with all the advanced options. Not everyone uses the disappearing messages option for example, and (until recently) all group members were effectively administrators, and so any member of a group could unilaterally switch off disappearing messages. Also until recently there was no way to boot someone from a group so if there was anxiety about a person being disruptive, not participating, or having poor security practices the only option was to create a new group and add everyone except that person, which becomes a big administrative headache once you have more than a few people.