After staff at Pennsylvania prisons were sickened by synthetic drugs, the state cracked down on its mail policy. It mandated that guards photocopy inmates’ mail — including legal correspondence with their attorneys — and give the copies to the inmates, while keeping the originals. The policy spurred a lawsuit by the ACLU and other criminal justice groups who claimed it breeched inmates’ First Amendment rights. It also raised the question of what takes precedent: the safety and security of prisons or the protection of attorney-client privilege? On this episode of The Why, Katie Meyer, who covers the State Capital for WHYY and other Pennsylvania stations, explains why legal mail privacy matters.