The United States has experienced extensive controversy about government surveillance, including the collection of phone, e-mail and Internet search data, in the name of national security, the prevention of terrorism, and the saving of American lives.While some have seen the domestic spying as necessary in a globalized world where terrorists can more easily seek to carry out operations undetected, others have decried the work as being a violation of citizen liberties.In this way, the debate reflects the tension and contradiction inherent in the assertion found in the Declaration of Independence that governments are created to protect: