[nattmat]

By using an append-only Merkle tree, you make 'edits' by adding a new piece of data with information on what was changed in the older data. You get the benefit of also keeping a version history. I think Git works like this.

[palunon]

Note that Git commit graph isn't really a tree, but a directed acyclic graph, in which nodes (commits) points to actual Merkle trees (trees/blobs).

(Also, git keeps the full data, not only diffs)

[yosito]

Interesting. I suppose deleting sensitive data is a more difficult challenge.