I'm sure at least 99.9% of people here would agree that a cheater or hacker completely ruins the immersion and challenge of an online game - the 0.1% that disagrees are likely the hackers themselves. ;) Thankfully with the advent of things such as Valve's Anti-Cheat and other initiatives being made, I can at least personally say it isn't something I deal with as much as I used to (Even if I still grumble about some BS headshots!)
Which is why a smile is always brought to my face when I see articles such as this one: http://www.pcgamer.com/pubg-cheaters/
"We have also been working hard to tackle down cheating players. This is an ongoing battle, but one we are committed to fighting... ...We have banned 25,000+ users in the last 3 months, and work daily with BattlEye to add new protections and detections for cheats appearing on the market." -- PlayerUnknown
Even if that is only approx. 0.6% of the total playerbase, you have to start somewhere!
Has there been any major game franchises lately where you've experienced a hacker? The Division was one that came to my mind, but I'd love to hear your own stories of both grievance and triumph when coming across a hacker... And the rare instance where they are just so bad at the game, you beat them anyway!