How does Farcaster handle deletion/ephemerality? Or is everything just on a blockchain forever

I’m also curious about this for Farcaster, and for Lens. As an experiment, I made a post on Lens, collected an NFT of it, then deleted the original post and the metadata of the collected NFT persists. Unsure if it’s possible to get it taken down from IPFS.

it's not repudiable but the content (not hash) is removed as part of set construction

> Short Text Casts for a user are stored in a two-phase set CRDT3, which contains an add-set that stores additions and a rem-set which stores removes.

Technowatermelon. Elder Millenial. Building Farcaster. 

nf.td/varun

I believe casts are just marked deleted and it is up to clients to observe that or not. Casts aren't on chain either, but rather on farcaster protocol hubs. @dwr.eth & @v can correct me where I am wrong and go into much more detail.