To add some practical context to this insightful comment: in Belgium, 1-on-1 conversations are considered private and as such protected, meaning you need a judge order to listen in. However, If the conversation is professional, both parties are allowed to record it.

Now, any conversation with 3 or more parties is considered public. A closed group chat on whatsapp has the same legal protection as shouting it on a megaphone to a crowd, meaning none whatsoever and people have already been convicted for their speech in closed chats or forums.