SAN FRANCISCO: US President Barack Obama named Twitter's chief and a high-ranking Microsoft executive among a handful of technology veterans to be appointed as telecommunications security advisors. “I am proud to appoint such impressive men and women to these important roles, and I am grateful they have agreed to lend their considerable talents to this administration,” Obama said in a White House press release available online Friday. “I look forward to working with them in the months and years ahead,” he continued in reference to those he picked to join his National Security Telecommunications Advisory Committee. The list of appointees included Twitter chief executive Dick Costolo; Microsoft vice president of trustworthy computing Scott Charney; McAfee computer security company president David DeWalt, and Lisa Hook, head of global communications technology firm Neustar. The final appointee to the committee was Jamie Dos Santos, chief of the group that handles federal government information technology at Terremark Worldwide. Costolo replaced Twitter co-founder Evan Williams as chief executive in October in a move that gave the San Francisco-based firm's helm to a Google veteran with a mandate to help the microblogging sensation make money.