Filtering Internet ceritera in Iran is annoying people and expencive, head of Iranian Parliament(Majlis) research center told in an interview with mehrnews.
He warns cost of harrasment internet filtering! and about recent shutdown of many Iranian websites and filtering he said:"even if security is justified, should be explained by the authorities because increase people trust to government and people accept the security and cyberpolice justification"
Recent filtering and blocking of Google,Yahoo,MSN without any perior information from autorities bring Islamic republic of Iran above China in internet censorship list.
Internet censorship can also come about due to events such as the Arab Spring, which led to instances of censorship in an attempt to undermine the protesters.