Do you think social media is making people do stupid things they wouldn't otherwise do? This one wouldn't really mean the cat had to die but we don't know what happened to it. I still think the kid is probably a sociopath but is he more influenced by today's society? https://www.yahoo.com/news/teen-arrested-disturbing-kitten-abuse-233203241.html
Society at large has a dampening effect on our worst urges (societal norms, laws, expectations, etc) but cliques/groups you choose to hang out with have an amplifying effect, at times, on your main personality traits. Social media hasn't fundamentally changed that, it's just made it easier to connect with groups of people you otherwise may not have had exposure to. So it's entirely possible that social media had an effect, in allowing him to find a group of "friends" that encouraged this aspect of himself and egged him on, that he may not have found in the course of normal life, but I don't think that reduces his own guilt. You're a product of all the choices you make--who to spend time with, what parts of yourself you try to limit or grow and, ultimately, whether you choose to abuse an animal or person. He made poor choices, probably even before what he did to the kitten, and we blame/credit people for choices.
I always thought it crazy when two people would find each other and they shared the same sickness. Like men that attack women with an accomplice. I thought the odds of one psycho finding another one were small. It is scary to think of them finding each other so easily now.
The Democratic Party has weakened our Justice System not only by their shameless personal examples, but by selectively refusing to enforce certain laws, by selectively refusing to prosecute and imprison certain people, by enacting new laws which selectively incriminate citizens for reporting crimes being committed. Why bother acting responsibly when you are derided for it? Why not cheat, steal and lie when there are no consequences?