Some of the comments regarding cabling got me thinking about the purpose of cabling trees. I was taught that the primary purpose of cabling is to provide additional support for a weak crotch or other defect in order to prevent structural failure. Others seem to believe that a cable is meant to "catch" a failing trunk or limb to prevent it from striking a known target. Still others are opposed to cabling based on liability issues. What is the consensus here regarding the purpose of cabling and bracing in trees?