You bring up an interesting technical point (for me). Should the filtering be done at relay or the client? I am not clear on this. For now blocking people with extreme views seems to handle thing like hate speech, or child porn for example. But I do want to see people who have different views as long as it is not propaganda with no evidence or facts. Its not a fault of nostr, which I think is a good protocol. Maybe the "groups" feature in coracle will help. Still figuring things out, but very interesting stuff.