Nostr1.com from nostr:nprofile1qqs8eseg5zxak2hal8umuaa7laxgxjyll9uhyxp86c522shn9gj8crspzemhxue69uhkyetkduhxummnw3erztnrdakj7qg6waehxw309akx7cmtvfhhstnxd9shg6npvchxxmmd9uq3zamnwvaz7tmwdaehgu3wwa5kuef0rd95a7 you can setup a block list
The only way to truly block someone to the point that they can't see your posts either is to run your own relay that reads your blocklist and then refuses to feed your posts to people you've blocked.
Is there a relay that does that? Is there a NIP for that? nostr:nprofile1qqsrhuxx8l9ex335q7he0f09aej04zpazpl0ne2cgukyawd24mayt8gprfmhxue69uhkcmmrdd3x77pwve5kzar2v9nzucm0d5hsh2c3z4 nostr:nprofile1qqsyvrp9u6p0mfur9dfdru3d853tx9mdjuhkphxuxgfwmryja7zsvhqpzamhxue69uhhv6t5daezumn0wd68yvfwvdhk6tcpz9mhxue69uhkummnw3ezuamfdejj7qgwwaehxw309ahx7uewd3hkctcscpyug nostr:nprofile1qqsr9cvzwc652r4m83d86ykplrnm9dg5gwdvzzn8ameanlvut35wy3gpzdmhxw309aex2mrp0yhx5c34x5hxxmmdqyxhwumn8ghj7mn0wvhxcmmvqyg8wumn8ghj7mn0wd68ytnvv9hxgpywa92 nostr:nprofile1qqsf03c2gsmx5ef4c9zmxvlew04gdh7u94afnknp33qvv3c94kvwxgsm3u0w6 nostr:nprofile1qqsdv8emcke7k3qqaldwv956tstu40ejg663gdsaayuuujs6pknw7jspr4mhxue69uhkummnw3ezucnfw33k76twv4ezuum0vd5kzmp0qy88wumn8ghj7mn0wvhxcmmv9uq3yamnwvaz7tm0de3ksctfdch8qatz9u4777tf
Discussion
yes, this kind of setup is possible on https://relay.tools aka nostr1.com
fiatjaf also has a nice relay for experimentation that automatically adjusts the acl list to only show your notes to people you follow
mainstream clients though most will leak your note when someone else reacts or replies. so its best to discourage your friends entering the relay into their relay list unless they know what they're doing (use jumble etc)
lockbox.fiatjaf.com