The FBI is asking Internet companies not to oppose a controversial proposal that would require firms, including Microsoft, Facebook, Yahoo, and Google, to build in backdoors for government surveillance. In meetings with industry representatives, the White House, and U.S. senators, senior FBI officials argue the dramatic shift in communication from the telephone system to the Internet has made it far more difficult for agents to wiretap Americans suspected of illegal activities, CNET has learned. The FBI general counsel's office has drafted a proposed law that the bureau claims is the best solution: requiring that social-networking Web sites and providers of VoIP, instant messaging, and Web e-mail alter their code to ensure their products are wiretap-friendly.