Using someone else's music, footage, or images without a license can lead to copyright strikes or demonetization, and 'fair use' is a narrow legal defense — not an automatic right — that depends on factors like how much was used and whether the new work transforms the original. Honest disclosure of sponsored content (clearly telling your audience when a video is paid for by a brand) is both an ethical obligation and, in many jurisdictions, a legal requirement, since undisclosed advertising misleads viewers. Every platform has community guidelines covering harassment, misinformation, and prohibited content, and repeated violations can result in demonetization or account termination regardless of how large your audience is. Protecting your own content — understanding how to report unauthorized reuse — matters just as much as respecting the rights of others.