Nope once a note is posted it stays on the relays.
Unless the relay goes down it’s permanent.
So freedom of speech here comes with responsibility. Don’t say something you will regret or used against you. 👍
Discussion
Not true, actually. Well, not entirely.
See here: https://github.com/nostr-protocol/nips/blob/master/09.md
Some clients support it, some don't. Most relay software like strfry and friends actually honor the request to delete - but, I wouldn't ever consider it a guarantee.
First I heard of this. Interesting 🤔 💭