Most people are not crooked and won't be doing this. Probably 99% I would say. But do you ever think that you're writing and ideas are susceptible to people who look at them and mine for ideas if not outright copy them? They'd just log on, browse, and when they come across something cool, they would be like, "Hmmmm...that's good" and they would copy it or imitate because you're too obscure to matter and most likely not to get caught. Especially when you cannot control your posts and even then, I hear the posts don't disappear, but go through a secondary optional deletion by moderators.
You can't copyright ideas. And even so, each writer would write the same idea differently. In the end, what counts is execution more than ideas.
Not if it happened to you, lol. But very true...sounds a bit cutthroat in a way. Guess I should be wary about what I post.
Look at song covers by various artists. Same words, same music, totally different products. Examine John Denver's "Take me home, Country roads", Toots & the Maytals' "Take Me Home, Country Roads", and any garag-band's cover (all of these can be found on youtube). As I pointed out with the SSC's you can take an idea, character set, and theme, give it to 20 people, and get 20 different stories. Plagiarism arises when a person rips you off verbatim and claims to be the author. That is really rare, and almost always the person gets caught (eventually). I don't loose much sleep over it.
Thing about those covers is, you have to pay the original artist a licensing fee (or you're supposed to). ASCAP and BMI send people around to look for cover bands and then they send out demand letters or file lawsuits for royalties. And they win them.
There's a difference between covering a song, in which you acknowledge the original songwriter and pay royalties, and covering a song and claiming you wrote it yourself. The second is plagiarism; the first is not.
This is true. And of course you are free to write your own song addressing the same themes and ideas.