Sometimes I think I might have involuntarily committed copyright infringement, in the form of paraphrasing very closely to what someone else has already said. Sometimes I post something, and when I re-read it, I think it sounds eerily similar to something that Uncle Jim or Victoria or TNH had said before.
That's only for posts of factual information. Otherwise, I've never committed copyright infringement.
(Okay, I admit it, I wrote a "chapter" for my side-project based on the spam poem "I am Mrs. Miriam Abacha a Widow" by TNH. But that's classified information.
It is hella funny though. You'll get to read it eventually.)