NSA's a black box whose sole purpose is the aggregation and analysis of any information with potential relevance to US national security. It has the capacity to compel or infiltrate companies like Facebook to make them cooperate with its goals, and data sharing agreements with multiple nations. Privacy violation isn't a side-effect of its business model, it's its raison d'être.

I wouldn't dismiss NSA so offhandedly along this metric, even if it's ostensibly more constrained along legal boundaries.