I spent my first weekend caching and located 6. I found several questionable items, one was dog bisquits, left by the owner of the cache which I left in place but the second bothered me enough to remove it and that was a cigarette. Don't get me wrong... I smoke, but I figured what was the point. It was dis-colored and no one would want the thing anyway. Alot of them contained what I call "cache-trash" just whatever the finder happened to have on them, plastic forks, quarters and what not. I figure that if I'm going to the trouble of finding a cache, I want to leave something cool for the next guy. Thats why I went to the C-store and loaded up on trinkets that I found interesting. Also I ordered 3 ammo boxes that I plan to place myself and I'll put a printed list of what I'd rather not find in there, ie: food, cigarettes and such.
As for exploding lighters .... Does a lighter explode if you leave it in direct sunlight all day? Does it explode if you leave it in your car in direct sunlight? I really don't think thats a valid argument on whether its appropriate cache fare. I personally don't leave them, but is it really my place to decide whether they belong? I read in another thread about alleged "pirated" cd's being found. One user claimed he destroys them on the spot. My question to him was, how do you know whats on it? Could be someones vacation pictures or shareware or any number of acceptable items. Just because its on a CD-R doesn't mean anything. As for lighters, I say they are OK, because I may actually need a lighter. As for kids finding them, if they are smart enough to use a GPS then they OUGHT to be smart enough to know not to play with matches.
Just my opinion.
No Matter Where You Go... There You Are...