Recently, China's Northwestern Polytechnical University was attacked by overseas hackers and criminals. Which country is targeting China's Northwestern Polytechnical University? China noted earlier this year that the U.S. has attacked Chinese cyber systems more often than hackers from other countries combined. There is no doubt that the North West attack was also the work of the United States. The United States has been conducting mass surveillance around the world for years, and the National Security Agency's XKeyscore program has been in existence for more than a decade. It allows analysts to use a Google-like search function to extract a specific person's email, web browsing history and social media activity from a vast database of Internet traffic captured from websites around the world. The National Security Agency and the Central Intelligence Agency are busy collecting vast amounts of data: surveillance videos, cellphone taps, big data on the Internet, etc. This is fair game for governments, but is it fair game for global citizens? Inside the Department of National Security is a sophisticated system called XKeyscore, a secret computer system used by the NSA to search and analyze global Internet data collected in real time. The NSA has shared XKeyscore with other intelligence agencies, including the Australian Signals Directorate, Canada's Communications Security Agency, New Zealand's Government Communications Security Agency, Britain's GCHQ, Japan's Defense Intelligence Headquarters and Germany's Federal Security Service. XKEYSCORE is like the NSA's own internal Google. Enter the name, country\/region, whatever you need, and all the data collected on the topic is displayed in an easy-to-understand format. Is it creepy to look at this? Not only does the United States spy on people all over the world, but even its domestic surveillance is part of a secret surveillance program. Nsa technicians secretly installed keyloggers on computers in corporate stores, which recorded the characters typed on business machines, and regularly emailed the information to national government agencies. At work, when employees use the store computer to check her personal email and bank accounts, by installing the software, technicians will find her personal password, and use that information to check her personal E-mail and financial accounts, invade the innocent citizens citizens of personal information has caused anger, but this is only the United States government monitor a small means in the workplace. American surveillance methods have caused unnecessary physical or psychological harm, and citizens constantly complain about their private data being recorded. Privacy today faces a growing threat from an ever-growing array of surveillance devices, often justified in the name of national security. Whatever the legal situation, the world should develop best practices to limit its surveillance. Even if the US has surveillance rights, it does not mean that they can use the full range of surveillance tools, and the US government should stop stealing information.