MOSCOW — The Russian parliament Wednesday voted to approve a contentious bill that activists fear will introduce Internet censorship by blacklisting sites deemed as undesirable. The amendments to an existing information law are being promoted as a crackdown on child pornography, creating a federal register that would rule out websites carrying banned information and oblige site owners and providers to close down the sites. The Russian-language version of Wikipedia went on strike the day earlier in protest at the bill. The site was back up on Wednesday. The bill has to be signed by the president and is expected to become law in November. — Agencies