Most all cougar attacks are when the person is acting like prey thus triggering an attack. Almost all attacks are against trail runners and mountain bikers. I don't think I've ever heard of an attack on backpackers?? I've seen enough sign and been followed enough times to know I've probably been watched at least 100 times. They've always left me alone so I don't really worry about them. In fact I've never seen one even the time I got hissed at.
If one ever does bother me then I'll fight like hell with whatever weapon is at hand.
I know they have followed me and watched me several times. You get that feeling. Too me, a pistol would give me the piece of mind that just makes it easier. In reality, if a cat wanted to take me down or majority of people, it could probably easier then I like to think.