The great shopping-mall cellphone-tracking experiment of 2011 has come to a halt, thanks to the actions of an activist U.S. senator. Forest City Commercial Management said on Friday that it was suspending its trial of the FootPath customer-tracking system after Sen. Chuck Schumer, D-N.Y., raised concerns. “Even though all information gathered by the system is anonymous, some consumers may still wish not to participate,” Forest City spokesman Jeff Linton told the Associated Press.