Never allow them to do it again.
Never surrender your American Values and Freedoms because of fear or politics.
"These acts of mass murder were intended to frighten our nation into chaos and retreat. But they have failed; our country is strong. A great people has been moved to defend a great nation. Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America. These acts shattered steel, but they cannot dent the steel of American resolve. America was targeted for attack because we're the brightest beacon for freedom and opportunity in the world. And no one will keep that light from shining. - President George W. Bush, from his 9/11 address."