Visitors to the upcoming Olympic Games in Sochi, Russia, will be able to access the Internet faster and in more places than any previous Olympics, all for free to guests. However Russia’s FSB security service is reportedly installing a sweeping and invasive surveillance service to ensure that they will be able to intercept, read and even filter every digital communication passing through the city’s telephone and Internet networks during the game, leading to many security experts suggesting that visitors leave their devices at home.

Reports from the Guardian newspaper and Russian investigative journalism website state that the FSB has modernized its national electronic surveillance system and modified all telephone and WiFi systems around Sochi in order to ensure full access to all traffic and force servers to disable encryption systems.

A U.S. State Department warning recommends that travelers to Sochi might consider leaving laptops and smartphones at home.

According to documents that the journalists at have seen, the Russian telecommunications company Rostelecom is installing DPI (Deep Packet Inspection) on all its mobile networks, which would enable the FSB not only to read messages, but also to alter them and reroute them at will, the Christian Science Monitor reports.