Sometimes I do want to see the messages of people I did not subscribe to. For example when they reply to my message. In this case I need to have some filtering

Sometimes I do want to see the messages of people I did not subscribe to. For example when they reply to my message. In this case I need to have some filtering (read: moderation) system in place that ensures I do not get overwhelmed with spam, or gore[1] for that matter. [1] of course the beauty of a distributed system is that those who want to see gore can not be denied this right.