Using Libravatar by default is a privacy weakness

[Changaco]

Using Libravatar leaks the MD5 hash of the account's primary email address, so it should be opt-in, not opt-out.

[jaschaurbach]

Why not change to a SHA256 Hash instead? the MD5 was always only meant to ensure Gravatar compatibility.

Reference: https://wiki.libravatar.org/api/

[Changaco]

Why not change to a SHA256 Hash instead?

Because leaking a SHA256 hash isn't really better than leaking an MD5, and because we would lose the automatic fallback to Gravatar.