[8note]

Based on https://web.dev/floc/#floc-server it looks exactly like an ml class, rather than a hash.

Almost certainly your browser history is summarized into a vector, and then the closest class number is chosen and sent.

You might not know which vector the number represents, but it does represent a vector for the centroid, and has relationships with other cohorts.

I'd say it's guaranteed that that interface is leaky