It is an unfortunate reality of online gaming (and for that matter, human nature) that there exists a certain kind of individual who seemingly has no other purpose in life than to be needlessly hateful or otherwise unpleasant against others. Such people tend to dedicate an abnormal amount of time and effort into going beyond insulting someone and inevitably making things very uncomfortable for all, or they could simply act in a manner that is tantamount to bullying, or they might even be cheating/using exploits and ruining everyone's experience, leading many to dub such behavior as being "toxic," though there are undoubtedly a cruder set of words that you can use. Of course, it is understandable that emotions can sometimes flare up in games or any other activity, and it would be hypocritical to say that anyone who has called anyone else a [insert expletive of choice here] is toxic, but legitimately toxic individuals take such behavior to a level that is only slightly less severe than tire-slashing or mild arson. In fact, toxicity is such a worrying problem in online games like Overwatch that Blizzard's Vice President and Overwatch Game Director, Jeff Kaplan, dedicated an entire developer update to address the issue.
Most people would agree that part of the reason why toxicity in games has become such a rising issue is that it is far too easy to be a toxic individual. We are living in an era where you can instantly say anything at all to anyone anywhere in the world at any time with little to no repercussions at all thanks to the vital and necessary freedom of anonymity on the Internet, and short of curtailing such freedoms, there is little that anyone can do to make it harder for toxic people to be toxic. A person's upbringing would likely be a contributing factor as well, as could a whole host of other reasons, but it more or less boils down to the individual. You can possibly also point a finger at real life celebrities and online personalities on places like Twitch or YouTube, as it would be naive to say that such people don't influence others to some degree even if they are doing something that is completely innocent, though that is neither here nor there. Thus, it often falls to the developers of games like Overwatch, League of Legends, Dota 2, and so on and so forth to be the first line of defense against toxicity.
Naturally, a game's audience must have some easy way of reporting someone, and most importantly, the developer has to act upon such reports. That's not to say that false reports won't occur, but if there is a properly maintained and monitored report and appeals system, then such incidents should theoretically be kept to a minimum. Without proper support for one or the other, then the whole system may as well not exist. A failure to act upon user reports can and will lead to a lack of faith in the system, which leads to less reporting of legitimate troublemakers, and so on and so forth. A prime example of a developer failing to inspire faith in their own reporting system can be seen when Mr. Kaplan confronted someone on the Blizzard forums who was complaining about their ban; while it is a public show of force that Blizzard will ban you for being toxic in Overwatch, the fact that the banned account had over 2,000 complaints filed against it is unacceptable. To put this into perspective, that is roughly 4 or 5 reports a day for 15 months until Blizzard presumably decided enough was enough. Causing someone to report you for bad behavior once a day for an entire month should be more than enough probable cause for Blizzard to investigate the account at the very least, and yet here is someone who conceivably got reported by entire teams or even lobbies full of people and only recently got banned. It may be an extreme example (of a playerbase of roughly 30 million, only 480,000 people, or barely 1% of the population, have had their accounts "punished"), but the fact that this example exists to begin with is embarrassing.
As time goes on, such extreme examples will only get worse, or at the very least, they're not going to go away. The Internet has provided a means for toxic individuals to easily spread their poor habits onto others, and more drastic actions than a simple account ban may be worth looking into to help curtail this. Such a line of thought is dangerous, but at some point Blizzard and other developers may have to outright block people's IP addresses and credit cards from being used to access their products and services, or otherwise use methods that say "We don't want your behavior or your money." Cracking down on Twitch streams and YouTube videos that blatantly show someone using cheats, throwing games, and consistently behaving in a blatantly unacceptable manner may also help, or at least serve as a strong warning that such behavior will not be tolerated in any form.
Perhaps it may even be a good idea for developers to dial down the amount of ... stimulation that their games provide, seeing as how people can use in-game performance to hyper-inflate their own feelings of self-worth or superiority, thus acting as a vector for toxicity. No one's saying that games like Overwatch should turn into Water Pistol Fight Simulator, but we have to ask whether or not there is some kind of link between getting an audiovisual reward for merely getting an assist and acting like the rest of your team did nothing even though that's just not how the game works.
All that being said, toxicity and its causes are a very complicated psychological issue to tackle, and it is the responsibility of all of us, not just game developers, to make sure that our favorite games don't become a cesspool of bad behavior thanks to the actions of the few. Regardless of whether it's Overwatch or Halo or Counter-Strike or Minecraft, we all have a responsibility to make sure that some otherwise benign act of frustration doesn't turn into something else. It is no secret that the censorship of certain words or phrases or bad-behavior quarantine lobbies have worked to some degree in the past, and it may be time for all developers to consider the standardization of such features across all multiplayer-centric games to protect the majority from a cancerous toxic minority. Splatoon 2 even goes so far as to disable voice chat with random strangers so that you can only talk with your friends, though one can argue that this is a bit extreme since, well, you can't exactly make friends in a game if you can't talk to random people. Either way, playing nice and playing fair should be a maxim that all abide by, for the benefit of all.