The DMCA is a US copyright law whose notice-and-takedown process lets rights holders request removal of infringing content from hosts, platforms, and search engines. For video owners it is the main legal tool against pirated copies, though takedowns are reactive and slow compared with technical prevention like DRM.
The DMCA (Digital Millennium Copyright Act) is a US copyright law best known for its notice-and-takedown process, which lets rights holders request that hosts, platforms, and search engines remove infringing content. Many other countries have equivalent mechanisms.
The copyright owner sends a formal notice identifying the infringing material and asserting ownership to the platform hosting it or to a search engine indexing it. On valid notices, compliant services remove or delist the content, and search engines can drop pirated links from results.
DMCA takedowns are a necessary tool but a costly, ongoing one. Preventing leaks in the first place with DRM, watermarking, and access control is generally cheaper and more effective than chasing copies after the fact.