[brazzy]

Could it be as simple as Google knowing that someone (namely, you) has previously searched for both these names, thereby establishing a connection between them?

I'm not sure whether that should be considered a privacy violation,

[greyman]

Yes, in my opinion, that would be a privacy violation.

[brazzy]

Why exactly, though? And can you suggest a practical solution that does not involve banning query correlation entirely (I don't think anyone is opposed to the idea of showing "Fred Astaire" and "Ginger Rogers" as related because many people search for both of them)