Weeks after a U.N. special rapporteur released a surprise open letter slamming a state-backed conspiracy bill that critics warn could erode privacy and free speech rights, the Cabinet of Prime Minister Shinzo Abe has shown no sign of letting up on its targeting of the statement.

If anything, it has been hellbent on discrediting what it claims was an "inappropriate" rebuke by the United Nations expert.

Tokyo's ongoing clash with Joseph Cannataci, a U.N.-commissioned expert on the right to privacy, is reminiscent of a similar war of words it has fought with U.N. special rapporteurs in recent years. Many of the probes by those officials into the human rights situation in Japan have led to conclusions often at odds with the government line.