What we see on Facebook (maybe some of the other social media services are a little different) is a signaling of tribal allegiance. Democrat or Republican. Pro Life or Pro Choice. Pro ICE or anti-ICE.
When people post things (or often, repost using the share function) that is much of what is going on. Many individuals don’t think hard along the lines of “Hmmm, is this thing I’m about to post or share or comment actually *true*?” They go by their tribal affiliation, as it were. Additionally, many people share just to demonstrate that they are active, rather than lurking or never even logging in.
My favorite recent post on this issue is the digressive but analytically sharp Substack post
“Because it’s wrong” by Mark Atwood. (I’d never heard of him until finding the post, which doesn’t mean anything much). The disconcerting theme of Mark Atwood’s post is that for many people, most of what they say or write or share or repeat is, to use his languge, “a move.” Truth is not a concern.
To quote him,
“In any social environment where statements are understood as moves (corporate, political, academic, activist, media), every public assertion is assumed to be strategic. You say things to advance your position, to signal your affiliation, to attack your opponents, to build your brand. Communication is a game. Every utterance is a play. The question is never just “what did he say.” The question is “what is he doing by saying it.” “
__________
I’m baaaack!
Here is a recent (and representative) Facebook post from a Facebook friend, a neighbor, a tutor who has been very caring and kind to me since the death of my wife. She is wildly Trump Deranged, and, frankly, too smart to hold and proclaim many of the opinions she rants about on Facebook. In fact, she is brilliant in many ways, and isn’t shy about saying so. I don’t think she has any idea how obnoxious and ignorant I find her posts; the woman is genuinely obsessed. But I do like her, she’s a good, ethical human being, and it isn’t worth the cost to me to explain on Facebook why she’s making an ass of herself.
Here she defends Macklemore, the anti-Israel rapper—I was going to post about him, but I’m hitch-hiking on Charles’ COTD instead— who appeared on stage like this

….while making his usual vicious anti-Semitic attacks. Note my friend’s desperate rationalizing away as clear an instance of deliberately employing negative Jewish stereotypes as you could find going back to Shakespeare’s times. Would she defend an artist who appeared in blackface? Believe me: never! Incredibly, she actually stoops to “Some of my best friends are Jewish,” the mantra of the guilty bigot!
I hadn’t heard that one since I was an undergrad at Harvard….
Fuck Trump. Fuck ICE. Free Palestine…I am as far from antisemitic as anyone can be; the two men I have loved and most of the people in my life are Jewish. So enough of this garbage! Face that Israel and the violence it perpetrates against innocent people is not related to your religion. Do your best to separate yourself from a violent genocide and where you worship. They are very distinct items at this point. 
Macklemore does not have anti-Semitic baggage anymore than Mark Ruffalo or the members of Coldplay do. Macklemore is well known for crazy clothes and costumes. Take a look at the images of him over the years and recognize that throwing some mask on is a small part of his approach to throwing together insane outfits. The man literally only buys his clothing at thrift shops, and he was just trying to enjoy a show without being recognized. And if you can’t accept it, recognize that the. Anti-Defamation League did. Maybe consider the decisions of the people who actually research these matters?
Macklemore stated that he did not intend to dress up as a Jewish person, explaining that the costume was meant as a random disguise.In May 2014, Macklemore wore a fake hooked nose, a black beard, and a wig during a surprise, unannounced pop-up performance at the EMP Museum in Seattle.The Explanation: The rapper released a statement saying he assembled the pieces randomly just to disguise himself so he could walk through the crowd and watch the show anonymously before taking the stage. He stated that portraying a Jewish stereotype or putting down any culture “never crossed my mind” and that he just happened to “love a weird outfit from time to time.” The Apology: After immediate online backlash and accusations of invoking an antisemitic caricature, Macklemore apologized, acknowledging that the outfit could look like a harmful stereotype within the context of cultural caricatures. The Anti-Defamation League (ADL) accepted his apology.
If you’d like for me to start posting photographs of the crazy shit that Macklemore has worn in public since his music became popular, I’ll do it. No one is going to accuse this man of being antisemitic because he spoke out against the massacre of 20,000 innocent children. Stop trying to make excuses for a genocide because you are Jewish. It is utterly unacceptable. Your religion has nothing to do with what the state of Israel is doing in Palestine. 
On top of all that, this man goes out in public dressed like a lunatic every single day of his life. Are the lobsters offended because he once dressed like a lobster? You’ve got to see the way this guy dresses every single day of his life. I’m sorry you haven’t enjoyed his music, but I have. And I have seen hundreds of crazy ass outfits on him.