Agreed. Also what's being overlooked by others is the inability (using dumps of "users of site X") is the ability to globally intersect that with another site.
The ability to quickly find users who have an account in (list of embarrassing sites) intersected with (list of internal gov and mil sites, and large defence companies) is hugely powerful to some adversaries, and data leaks/dumps only give half of this equation.
The ability to quickly find users who have an account in (list of embarrassing sites) intersected with (list of internal gov and mil sites, and large defence companies) is hugely powerful to some adversaries, and data leaks/dumps only give half of this equation.