If you are posting text content to your Steem blog, you can be reassured that if anyone else tries to pass it off as their own work, you can use the blockchain as evidence to refute this. This is another great benefit of using a blockchain based blog for your content.
Unfortunately, it isn't possible to your store any photographs, videos or music in the blockchain (they are stored on ordinary web servers) so it's not so simple to prove that they are your own work.
I have created a simple tool, which creates a hash of any file you select, and allows you to paste it directly into your blog, as a form of protection.
The hash is a digital signature, and acts as a representation of your file, that nobody without your file can recreate. When you paste it into your blog it shows (in the public blockchain record) that you had the file at the time of posting.
With this SHA256 hash, and your original file, you could fairly easily demonstrate for example that somebody had copied your musical idea, or stolen your photograph.
I'm a musician (and also post as @andybets). Several years ago I was a victim to this kind of behaviour where a few of my original songs were posted online by another person who claimed they were his. It's not about money for me (I'm not a professional musician), but there is something really annoying about it, so when I started posting on Steemit, I decided to use this approach to protect my original media from any similar situations. You can see the code at the bottom of my open mic entries.
I don't know whether the evidence this technique provides is legally admissible or not.