They can become problem animals when crowded closer to human habitat. They get used to harvesting the new and easier prey, your dogs and cats, tamed deer which are all over cities in many areas of the USA, and a lot of smaller game and possibly children. Same thing happens with bear. They either have to be trapped and moved a long way, or shot. It is just a fact of life out west.
We lived at the edge of the woods for years out west. Saw sign of cougar, but only saw a couple in nearly 20 years, and bears were generally in my orchard every night as soon as the plums,apples and pear started to ripen and fall. I picked in the daylight, they picked at night.
Never had an issue with either. The elk and deer were destructive and in some situations kill permits were given to landowners if other measures failed.
Country folks have been living amongst these animals since the beginning of mankind and have managed the problem the same as they are trying in the city. If you don't want them, figure out a solution, we did.