"Call routing information, like all metadata, can only be protected legally not cryptographically." A counter example of this is seen through ImperialViolet's

"Call routing information, like all metadata, can only be protected legally not cryptographically." A counter example of this is seen through ImperialViolet's pond(https://pond.imperialviolet.org/ https://pond.imperialviolet.org/). Using pond, neither metadata nor content are leaked, as both are transmitted over tor every set interval.