American whistleblower Edward Snowden called it a "dark day for Russia" when Russian President Vladimir Putin signed into law what Snowden also dubbed as the "Big Brother law."

(REUTERS/SERGEI KARPUKHIN) Russian President Vladimir Putin addresses the Federal Assembly, including State Duma deputies, members of the Federation Council, regional governors and civil society representatives, at the Kremlin in Moscow, Russia, December 3, 2015.

The former National Security Agency employee, who lives in an undisclosed location in Russia after receiving asylum three years ago, took to Twitter on Thursday, July 7 to criticize the announcement made earlier that day that Putin passed into law the controversial anti-terrorism bill.

"#Putin has signed a repressive new law that violates not only human rights, but common sense. Dark day for #Russia," wrote Snowden.

The law, which Snowden also earlier dubbed as the "Big Brother law," makes it a crime to commit any act that may be perceived as inciting or expressing an approval of terrorism online as well as mere discussions of public demonstrations. It also obliges telecommunication providers to store records for six months and requires messaging services such as Facebook and Telegram to provide decryption keys to state authorities.

The new law also prohibits preaching, evangelizing, and distribution of religious materials outside one's home that could be penalized for up to $15,000. Churches are also restricted on their contact with foreign missionaries.

United States Commission on International Religious Freedom (USCIRF) issued a press release Friday to condemn the passing of the anti-terrorism bill which USCIRF said only took on "under the guise of confronting terrorism" to suppress religious and civil liberties. USCIRF believes the law targets religious communities such as experienced by Muslims and Jehovah's Witnesses as the country identifies extremism including religious acts of advocating "the superiority of one's own religion."

"The law has been passed along with a list of recommendations to the government designed to minimize potential financial risks," Putin's spokesman Dmitry Peskov told journalists, as reported by The Moscow Times.

"If the law produces any undesired outcomes, the government will introduce measures accordingly by presidential decree," added Peskov.

Also known as the "Yarovaya law" after its chief proponent, ultra-conservative lawmaker Irina Yarovaya, the new law will take effect July 20.