Once you have enabled AI Servo mode and selected the correct focus points (if you want to adjust them from how the camera is currently set up), the only control you need is the shutter button -- just pressing this halfway will enable focus tracking on the focus points that are enabled.
The Social Security Act was enacted August 14, 1935. The Act was drafted during President Franklin D. Roosevelt's first term by the President's Committee on Economic Security, under Frances Perkins, and passed by Congress as part of the New Deal.
Updated June 29, 2016. The Social Security Number Protection Act of 2010 was signed into law by President Obama in December of 2010, the same day he signed the Red Flags Clarification Act. This law originated in the Senate where it passed unanimously after being researched by the Senate Finance Committee.