The Joker movie is still 3 weeks away, but thanks the Venice and Toronto Film Festivals, reviews are coming in and some douchebags are sharing clips of the movie on twitter, because they are happy that the movie turned out to be good.
I want to see this movie in cinema, but in my town they usually don't show it with subtitles, and I want to enjoy the movie with that. English is my second language and I love watching movies in original language (no matter if it is German, Japanese or Spanish).
So in order to remain spoiler-free, I won't use social media until I watched the movie. And sadly that's including Youtube. People after the first they are creating videos, and sometimes they use spoilers in thumbnails, because they are idiots.
Also, Twitch is not a spoiler-free zone, since there are jackasses, who loves to spoil people's fan. That's how I ran into major Endgame spoilers by accident.
I guess reddit is the same, since they marked things with SPOILER, but if somebody makes a mistake you can still ruin your experience.
Also if you have friends... well friends are friends and hopefully they don't spoil the movie for you.