I've written about the problem with mountain lions before, mostly in the West. These cats clearly hunt humans. This is very different from deaths due to bear attack, where most of the attacks are from bears either searching for food in a poorly kept campsite, or bears which are startled on the trails and attack as a defense mechanism. Yes, the bears will go ahead and eat you once they've killed you, but it is very rare for bears to hunt humans for food.
That appears to be what large cats are now doing. The latest attack on Jim Hamm in California has all the signs that the cat wanted this guy for dinner. The cat attacked from behind, grasped onto Jim Hamm's head, and refused to let go of him even though Hamm's wife was pounding on the cat with a log, and even tried to stab the cat in the eye with a pen. This cat wanted a meal, found Jim Hamm particularly tempting, and wasn't about to let go without a fight. This attack was almost identical to another attack in the Denver area last year that was also clearly an attempt to get some food. A 7 year old boy, walking last in a file along a trail, was grabbed by his head by a cat that thought he was a good candidate for an easy meal. The family had to fight off the cat in that instance as well.
I'm not sure if the cats themselves have gotten more aggressive, whether their numbers are increasing dramatically enough to put pressure on their normal food sources, or whether the attacks are just getting reported more often. I don't think that the studies have been done to see which it is, or a combination of these or other factors.
The bottom line is this, if you go into the mountains where mountain lions hunt, you will look like food. You will look like really easy food, unless you fight back. That's what all prey does when a predator calls. The problem is, what to fight back with. We don't have the ability to outrun a mountain lion, and we can hardly outfight them by pitting our nails against theirs or our teeth against theirs. We can't even (morally) do what most prey does...hope to be just a bit bigger or faster than the other prey in the immediate area.
As for me, I know what I have for an advantage. With my opposable thumbs, I can grip a semi-automatic pistol. That's what I'll take on the trail with me. I gotta check up on what Colorado requires for a CCP.