The Chinese government is starting 2009 with a crusade to make the Internet safe for its young population to surf without encountering pornography. While Beijing has previously tried to crack down on obscenity, this time government officials are using some of their harshest language yet, threatening actions against 19 Internet companies — including China’s most popular search engine, Baidu, and Google. Both Baidu and Google also offer blogging services that the government said had been used to distribute obscene content.