I've been harassed in MANY different ways on here (from ostensibly left-wing people who are reeeeallly just looking for the thrill of leading their friends on a cyberbully adventure, to nazis, to people who spam rape-threats from multiple accounts), and the solution for all of them is the same: just ignore it.
even if it sucks, even if they're saying things you want to refute, even if you think refuting will help things because Everyone Will Understand if You Just Speak Clearly Enough. even if you want to vent publicly because you think you deserve that much, acknowledging them is almost always the wrong move. you're just pouring gas and making sure that those couple little sparks turn into a fire. and all of them love to see you upset, not just the nazis threatening rape. sucks when it's your own, but hey, hurt people hurt people!
engaging is bad for a few different reasons. the first is that these people feed on attention. reply publicly, and that will give someone enough juice to make a new account every few days for a year plus, sending you paragraphs of insults mixed with strange accusations. whereas if you'd ignored them, maybe that obsessive phase would've only lasted a couple weeks. genuinely, you can create your own stalkers by reacting.
the second is that by engaging publicly, you're platforming them. even if you just post literal puppies and rainbows, there will be people hate-following who are pissed off about how many notes your latest puppies and rainbows photo got (because if you got more notes than them, it's punching up). they will see you engaging with harassment and go, hey, I can do that too! and that's how you get harasser mitosis.
platforming also has another problem. most people are good, but by the sheer quantity of people you'll be exposed to online, some will be malicious. if you are refuting something incorrect ("I never killed that man because I wasn't even in Florida on that day!") they will go right to the original slander ("they killed that man in Florida"), copy/paste, and spread it. or they will forgo the copy/pasting and just let it mutate in their memory so that it's a whole new thing by the time they spread it ("they killed several men and women in Florida, and also California").
currently, I'm in the 'block everyone who could potentially hate-follow and harass me' phase, but there is also some danger to that, because people see blocking as you acknowledging them, which (depending on the person) might be enough gasoline to rev them up. but it does at least provide some barrier, because making new accounts to block evade takes a modicum of energy, and if they're continually starved of further interactions, that energy will eventually fade.
anyway, those are my cool strats! if you start gaining any sort of online numbers, you can do this to keep yourself a little bit sane and healthy. good luck!
prguitarman
titsay
jbbartram-illu
gummygunk
andulkaphoto
vaporwave
