Sue them, and take everything they’re worth.
No, that was a joke, I have never and will never take legal action against someone stealing my ideas.
Plagiarism is a very common issue within creative industries, and can be incredibly frustrating. It’s happened to me numerous times, and I initially found it very confusing.
On one hand, it’s a compliment, and puts you in the frontrunner position in comparison to whoever is copying you. On the other hand, that person just took something you spent hours on and claimed it as their own.
The first emotion is the one you should stick to. Sure, it’s frustrating, but there’s more to an idea than the finished product.
For an idea, concept or product to be great means that you’re the only person who can execute it.
For example, when I have an advert of mine copied, they haven’t really copied every element. They can steal the design, but the reason why it’s a good advert is also due to the promotion and the actual product/service we’re delivering customers.
In the end you’ll never be able to prevent people from stealing your ideas, but you can take pride in that others are incapable of making something better.
It’s part of why I release so much information on SirThorney. There’s nothing stopping people from copying the exact marketing plan I came up with for my record label or bakery, but I’m the only one who can make these brands work exactly how intended.