he is the agent of everything that's bad about our world.

TIL OP is literally Satan.

We serve food here, sir.

I have a 2 year old and live in Nevada. Now I know to avoid taking my kid to swim in warm fresh water ponds, so, kinda helpful?

He ripped you apart for the use of proverb/appeal to authority. You need to know your fallacies if you're gonna argue. An early game mistake, but you gotta roll with the punches.

OP is interested in those topics and he's posting them. I don't think there is malice in their intentions. Like I said, OP also posts good news. If there was ill-intention, then all of the posts would be "misery," and you may have a point. But that's not the case.

This is where you could have clarified your argument. Something to the effect of "I'm not trying to make the claim that OP was being actively malicious. I'm saying that he was adding to the greater misery of all people by posting negative news that has no effect on anybody outside the family it happened to." Remember to never use the phrase "I didn't say" it sounds whiny and people hate it.

Personally I'd add a paragraph here where I'd go off into a short diatribe about the 24 hour news cycle being accelerated by the internet. But that's a stylistic choice.

Again your final paragraph has conviction, which is good. But, this time you refered to an earlier argument which hurt you. You can reference the earlier paragraph, but he just claimed it didn't hold water and your response was "yes it does".

Consider instead: "As I said before "short quote from before". I don't believe that engaging with things I disagree with perpetuates them. Though, if you have a more effective way of speaking out about it, I'd love to hear it."*

List of fallacies: https://en.m.wikipedia.org/wiki/List_of_fallacies

For proper logic you want the formal fallacy list, for better arguing you want the informal list.

*Note: "I'd love to hear it" is a great way to end a part of the argument but it must (a) be specified with which part of the argument you're talking about and (b) be something beyond repute. It's a very helpful tool, but used carelessly, it will cut your hand.

Fair enough. I hope you'll consider reading it as that was intended to be a consolation before genuine critique, but you're your own person.