Content theft covers a video re-uploaded to another channel, an article republished word for word, photographs reused in someone else's advertising, and a paid course sitting on a leak site. What connects them is that the work itself is the thing taken, not the name attached to it.
The legal basis is copyright rather than trademark, and that distinction decides who can act. You own the copyright in what you make from the moment you make it, with no registration step in most countries, which is why an individual creator can pursue this while they may have nothing to file against an impersonator using an unregistered name.
Proving it is usually simpler than people expect. The earlier upload date, the project file, the raw footage, the higher-resolution original: any of these establishes which copy came first, and that is the question a platform is asking.
Not every reuse is theft. Commentary, review, criticism and parody can be lawful even when they use the whole work, and a notice filed against one of those tends to be reversed. The clean cases are straight re-uploads with nothing added, and redistribution of material that was sold.
How Fraudox handles it
Stolen content removal