One day I realized that someone from my friends list had shared one of my posts as if it were their own content… No tags, no credit. I’m getting angry, but I hesitate because they might think I’m overreacting. In your opinion, should I confront them and talk about it, or is it just a waste of energy?
I think there might be something else behind this. I mean, why did they specifically take your post, for example? Maybe they are unknowingly being annoying, or could it be that they are jealous of you? It’s weird to just steal content out of the blue.
Girl, don’t just stay silent about things like this. They will keep doing it as long as you remain quiet. Confront them openly and say, ‘This is my content, and I won’t allow anyone to steal my work.’ If she were my daughter, I would teach her this way.
I experienced something similar last year. A friend took one of my posts and shared it as it was, and then wrote a comment as if he had written it himself. I talked to him, and he said, ‘Oh, I didn’t think it would be a problem,’ but he hasn’t shared anything else since.
So, was the content you shared something very special? I mean, is it something that not everyone can do, or was it a general post? Depending on that, you might express your complaint more clearly.
I think this is very common. It’s become a habit on social media; people share others’ stuff without even adding sources, and they don’t see it as a problem at all. I’m sure that person thought, ‘nothing will happen.’
Let me add this as an update: the content really was something that required effort, think of it like a design work. So it’s not a general post, it’s something I put a lot of time into. Maybe that’s why I’ve been affected this much.
I think you should write directly in private. Clearly state, ‘You’ve shared my design but haven’t credited me; I’d appreciate it if you could fix that.’ Speaking in the environment can create unnecessary tension 
If this design is a serious original work and you can prove that it is used, you can actually take a step regarding intellectual property rights. But in such cases, it would be healthier to clearly express your complaint first.
I swear I will get angry, they have literally stolen the effort. I will say it loud enough for everyone in the friend group to hear. People like this will only do something if they are embarrassed.