That's true too! And I think definitely it would be better for people to give each other the benefit of the doubt on that before crying foul.
But I meant more the type of people who get upset about people reposting their meme, when it wasn't even their meme to begin with (eg when two people find a meme from somewhere else and post it, and one accuses the other of reposting, even though they both did - presumably because the other person's post got more popular).