By Joseph Menn SAN FRANCISCO (Reuters) – A year after Edward Snowden exposed the National Security Agencys mass surveillance programs, the major U.S. technology companies suffering from the fallout are uniting to shore up their defenses against government intrusion. Instead of aggressively lobbying Washington for reform, Google Inc, Microsoft Corp and other tech companies have made security advancements their top priority, adopting tools that make blanket interception of Internet activity more difficult. Its of course important for companies to do the things under our own control, and what we have under our own control is our own technology practices, Microsoft General Counsel Brad Smith told Reuters. There is a need for reform of government practices, but those will take longer. As part of a Reset the Net campaign now reaching a mainstream audience, Google on Wednesday said it was releasing a test version of a program allowing Gmail users to keep email encrypted until it reaches other Gmail users, without the company decrypting it in transit to display advertising.