I use the release whenever i have the camera on a tripod. Usually this is for night or evening shots. I also use it when I am photographing paintings and other art work again using a tripod. I also use it in conjunction with Canon's 30' extension to have the camera remote or extended in the air on a Bogen auto pole or a large light stand to get a better angle for example of a building. I occasionally have had it go into the lock position during an exposure. Just have to be careful.
Sometimes a photographer just needs a way of taking a shot without having to touch the shutter button on the camera. The Canon RS-80N3 Remote Switch is a one-touch lock type remote control switch that can be connected to the remote control socket of SLR cameras. It enables you to release the shutter from up to 0.8m/2.6 ft away from the camera eliminating camera shake problems. Used in combination with the optical 10 m/32 ft. ET-1000N3 extension cord you can control the camera from an even greater distance. This can be especially useful for the wild-life photography.