Honestly, the situation is far worse and nuanced than that. You can not determine whether content is infringing on copy write because of content alone. Copyrigh

Honestly, the situation is far worse and nuanced than that. You can not determine whether content is infringing on copy write because of content alone. Copyright depends on context. Situation 1. You buy a PDF ebook. You have legal rights the person use of this file, but you upload it to your cloud storage and it gets flagged. You cannot determine if the intent of uploading the PDF was to facilitate pirating, or because you have a pirates copy, or because you have the rights to it. Situation 2. You hire a wedding photographer, and they supply you with photos that you do not own the right to distribute because they retain copyright. This is the same as the above situation, but personalised. Would you like your cloud provider to delete any file, including your wedding photo backups, because it with matches a hash in a database? Situation 3. Copyright fair use. Much has been written on the subject, but this is where copyright falls over in a digital age. Fair use is complete indistinguishable from piracy from a flagging files by content perspective.