Is this a normal thing people do?

I just recently got out of a breakup, and while it was not a very long relationship, I did come to like the guy a lot and fell for him pretty heavily. He was very much an avoidant and didn’t really seem like he wanted to be in the relationship a lot of times for the most part, but I still did my best to be as great as a partner as I could be. Things didn’t work out, I found some weird shit on his iPod one day while he was at work and decided to call it quits after that. Unfortunately, we did end up hooking up afterwards, and he did string me along for a little bit, but then just completely started treating me like a complete stranger, which, I will admit, sort of made me spiral and say some pretty harsh things. Out of spite, I ended up following one of his friends on Instagram, and low and behold, I get a very nicely worded message basically telling me that I have no friends and he’s glad we broke up and how I speak to people is “weird” etc. etc. which made me realize my ex had definitely shown his friends my mental breakdown. His friend does not know the entire situation, and I’m pretty confident if he did he’d probably just mind his own business, but I’m pretty sure my ex is just contorting the story into whatever will make him look the best. Is it actually a normal thing for people to form a one-sided opinion and then completely berate the person on social media with having 50% context and not care to actually know the full story? At the end of the day it is what it is and I’m pretty secure with who I am, but it did slightly disturb me that someone could just be blatantly rude like that out of the blue.