Some YouTubers do use watermarks on their videos to protect their videos and to also increase brand recognition.
Using watermarks on your YouTube videos will allow viewers to see your brand every time they watch your YouTube videos.
Watermarks on YouTube videos also indicate the true source of where the video is from and makes it less likely to be stolen and easy to report to YouTube as copyright infringement.
Some people have uploaded others videos without realizing the watermark was on the video and got the video removed due to a copyright claim.
You can add a watermark to your YouTube video by using the YouTube branding option and embedding the watermark using video editing software and design a watermark which matches your brands identity.
A YouTube watermark should be square shaped, smaller than 1 MB in size and ideally 150 x 150 pixels and it should include your YouTube channels logo or icon and a subscribe button.
Watermarks work better on videos than they do on photos as watermarks are harder to remove from videos than photos although still possible.
The reason why you shouldn't watermark your photos is because watermarks on photos make the photos look bad and detract from the quality of the photo.
The watermark on the photo is also visually distracting and may discourage potential clients or other collaborators from using your work as a result of the noticeable watermark that ruins the photos composition.
Watermarks are also not very effective at preventing image or photo theft and are even easily removed with photo editing software.
Watermarks are now mainly just a useless photo protection measure.
It is illegal to remove watermarks from school photos and other photos but they are easily removed and many people do remove them even though it's illegal.
Removing watermarks even from school photos is considered copyright infringement as the watermark on the school photos signifies that the photo or image is owned by the photographer.
And by removing the watermark from that school photo without permission to use the image would be a violation of copyright law.
If you get caught using the school photo without the watermark you could be sued although some people do get by with removing the watermark.
I've removed watermarks from school photos and have used them for personal use and never had an issue but if you try to sell the photo or use it in other ways you may be caught and get into trouble.
Watermarks are a visual indicator of copyright ownership so removing those watermarks is trying to bypass copyright restrictions.
And depending on the jurisdiction, removing watermarks from school photos and other photos could lead to legal action including fines and other penalties.
If you need a copy of a school photo without the watermark you can contact the photography company and inquire about purchasing a license from them for a photo without the watermark.
Some schools also have specific guidelines regarding the use of school photos, so you should also consult the school about their policies before you make any changes.