I don't think people stealing your stuff is that big of a concern. For one, you would have proof that it was yours since you could show the project in your DAW and they couldn't. Also, you would have an earlier upload date. Aside from all that, I don't think a copyright would stop anybody who was scummy enough to do that. On top of all of those other things... the type of people who pull that crap aren't going to be getting more then 100 plays anyways, I have a tough time picturing it being worth your time to worry about imo... but yeah, it's obviously good to copyright your stuff if you can but if you never show your music to the world because you're afraid it'll be stolen then what are you going to do with it? You have to release it at some point and it's just as easy to download music off youtube or anything other platform. *end ramble