The CEOs for each company have backed the letter including Twitter’s CEO Dick Costolo who says: Unchecked, undisclosed government surveillance inhibits the free flow of information and restricts their voice. The principles we advance today would reform the current system to appropriately balance the needs of security and privacy while safeguarding the essential human right of free expression.Last week, Microsoft published a blog post criticising the US government for its surveillance practices, calling its collection of public’s data an “advanced persistent threat.”Read: NSA gathers nearly 5 billion call records a day worldwide >Read: Guardian editor defends publication of NSA leaks in the face of tough questioning > EIGHT OF THE world’s biggest technology companies have urged the US government to address its surveillance laws, and have highlighted a number of areas for reform.The companies – which include AOL, Apple, Facebook, Google, LinkedIn, Microsoft, Twitter, and Yahoo – have written an open letter demanding that the NSA change the practices and laws concerning the government’s surveillance of individuals and access to their information.It lists five areas for reform including limiting governments’ authority to collect users’ information, oversight and accountability, allowing companies to publish the number and details of government demands for user information, respecting the free flow of information and forming a process that helps avoid conflicts among different governments.In an open letter, the group say: We understand that governments have a duty to protect their citizens. But this summer’s revelations highlighted the urgent need to reform government surveillance practices worldwide. The balance in many countries has tipped too far in favor of the state and away from the rights of the individual — rights that are enshrined in our Constitution. This undermines the freedoms we all cherish. It’s time for a change.For our part, we are focused on keeping users’ data secure — deploying the latest encryption technology to prevent unauthorised surveillance on our networks and by pushing back on government requests to ensure that they are legal and reasonable in scope.