The events of 9/11 have directly impacted five ways federal laws and regulations changed.

Regarding Transportation Security Administration, blue-uniformed Transportation Security Administration agents are now at all airports and are one of the most visible legacies of 9/11. Soon after the attacks, as part of the Aviation and Transportation Security Act, Congress authorized the creation of the TSA where airports previously had used private security guards.

The USA Patriot Act, passed by Congress a little over a month after 9/11 and largely still in place today, amended numerous existing laws including the federal anti-money laundering statute and the Bank Secrecy Act of 1970, to make them tougher on terrorism.

The Foreign Intelligence Surveillance Act saw major changes, and major controversy, around privacy. The Foreign Intelligence Surveillance Act was amended in both 2001 and 2008, and lowered the legal bar for the government to engage in wiretapping and other surveillance practices.

Material support laws expand anti-terror efforts by allowing the U.S. Department of Justice to prosecute not only terrorists, but those who provide support like money, training and weaponry to terrorists.

The creation of the U.S. Department of Homeland Security, which combats terrorism and other threats domestically and has promulgated regulations on everything from border security to natural disaster management, is the main federal agency to emerge from the attacks. The department was created by the Homeland Security Act of 2002, absorbing and reorganizing 22 existing federal agencies that deal with domestic safety, law enforcement and immigration.

Edward McAndrew, a partner at Ballard Spahr, said DHS and the ability it has developed to share information about terrorist threats across government agencies and at times with the private sector, also has provided a model for the federal government in tackling other emerging threats — like cybersecurity. "It created a paradigm that is now being used in terms of defending against cyberattacks," said McAndrew.