Iran is threatening to permanently block WhatsApp and Instagram, which are very popular in the country. The U.S. internet company Meta has so far not responded to the letter sent by the Iranian authorities in early December, in which they demanded that the company open a representative office in the country and adapt its guidelines to those of the Islamic republic. "If Meta does not respond to our letter, this could be the prologue to a permanent block," National Cybercenter chief Abolhassan Firouzabadi said in a newspaper interview on December 17.