A federal appeals court has ruled that the National Security Agency’s bulk collection of Americans’ phone records was illegal. The program was exposed by NSA whistleblower Edward Snowden in 2013. Snowden tweeted on Wednesday, “The ruling of the court demolishes the longest-held defenses of mass surveillance. After taking into account the best of the government’s evidence, the court found the program unlawful and ineffective, establishing the government’s public claims of 'necessity' were deceitful.”