People who spy on metadata make dishonest claims like "it isn't an invasion of privacy since we are only collecting metadata".

> There's obviously a difference between metadata and other data,

No. Your metadata is my data; that's the point. "Meta" is an additional contextual characteristic of some (I'd say most) data.

This. Metadata for the intelligence commmunity is a double-edged sword: is it something less, meaning it’s OK to mass collect? Or is it more, meaning it’s enough to justify a killing?