when copyright infringing content is removed or "taken down" from a website, by the website owner, upon receipt of a DMCA Takedown Notice from their ISP / Hosting company. This notice is generated by the, or on behalf of, the illegally published content owner, distributor, publisher etc.
A DMCA notice informs a company, web host, search engine, or internet service provider that they are hosting or linking to material that infringes on a copyright. The party that receives the notice should take down the material in question as soon as possible.
The Digital Millennium Copyright Act (DMCA) is a United States copyright law
that implements .... Rapid7 notice that DMCA adversely affects good faith security
research by forbidding researchers from circumventing technological protection ...