Indicators are very important. It is important that they are used when they should be used and not used when they should not be used.
Some friends of mine were nearly killed on a motorcycle because their indicators did not cancel and they continued down a road with their left hand indicator on. A driver seeing that turned into the main road immediately in front of them and simply took them out.
Because of that I stripped the indicators off my motorcycle so I could not be taken in the same sort of accident. I used hand signals since then, its pretty hard to leave a hand signal on

.
Personally I do not trust indicators very much because of experiences like that, I watch the vehicle, how it is positioned in the road, which way it appears to be going to go rather than just relying on the indications which appear to be showing.