In my experience, this question almost always get asked at entirely the wrong time, and with the wrong focus.
There’s a lot of nuance, but let me hit the high points quickly. (This is United States of America law; YMMV outside of the USA – so some/many of these things may be very, very different for this case in the UK)
- You get copyright on your work the moment you put it in a fixed form (yes, a blog post counts).
- You can officially register your work with the US Copyright office. This is not required in the USA to gain copyright.
- Sending a self-addressed stamped envelope does nothing.
- Copyright does not cover your ideas, only the way you wrote/express them. That may, however, cover characters if they’re “distinctly delineated”.
So if a member of my writing group reads my awesome story about a person time-traveling back to meet Mark Twain and then writes their own story about a person time-traveling back to meet Mark Twain… it might be a jerky move, but it’s not a violation of copyright. If they take my story and put their name on it, then it is a violation of copyright…and would make the next writer’s group meeting very awkward.
Typically, though, it only matters when there’s money involved. Again, like in this case from earlier this week. Why? Because you’ve got to sue in order to do it. If someone copies your (already unpublishable) fanfic, what damages are you going to demonstrate in court?
Mostly I hear new authors (or people writing fanfic) worrying about critique groups or agents or editors outright stealing their story… but they don’t think critically about signing contracts giving over copyright. (Hint: Check when a contract asks for exclusive rights for the life of copyright. ) Or worse, posting the material somewhere online. There, your concern shouldn’t be copyright violations, but that you just gave away first print rights to your work, which means it will be much harder to get it published.
There’s a lot to this issue, more than I can cover in 300-odd words (and frankly, I’m not a lawyer). If you’re coming to Context this fall, we’ve got a presentation on intellectual property law, and for even more in-depth questions, I’d urge you to check out one of the literary lawyers that Laura Resnick lists.