YouTube's rules aren't very strict, but there are still a number of rules that creators need to follow. If you see a video on YouTube that you think is inappropriate or illegal, be it hate speech, pornographic, libelous, or otherwise improper, you can report the video to YouTube.
You will remain anonymous when reporting a YouTube video, while the report will go to a group of YouTube moderators to review. If the report is accepted, whoever posted the video will be told their content is under review. Any account that repeatedly posts inappropriate YouTube videos could ultimately be terminated and banned from the site.
How to report a YouTube video
1. While logged into your YouTube account, go to the video in question.
2. Click on the three dots below the video, to the right of the view count and title, and then hit "Report."
3. Select the primary reason you're reporting the video ("Spam or misleading," e.g.) and then select a specific reason from the dropdown menu that appears. If there are offensive links in the video, click the box that indicates as such. Click "Next" once you're done.
4. Mark down the timestamp where the offensive content occurs, and add any comments you have to support your report and tell moderators what to look for.
5. Click "Report" to confirm the report, and then let YouTube's moderators take care of the rest.