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.
The Canon RS-80N3 Remote Switch Shutter Release 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 2.6 feet (0.8m) away from the camera eliminating camera shake problems. A handy accessory for any camera kit.