Usage of Videos or Images from Youtube/ Google-images as data source I'm working on a deep neural network research application Does usage of youtube videos or google images as data source cause a sharing-data, ethical, copyright or commercial problem? The aim of the usage of these data is only academic research. Maybe we can neglect google-images because of there are many free image data set. But we need youtube videos because of time and cost. Instead of sharing data in the article, is sufficient to write: "this study uses top 10(or more) search results for keyword search on youtube/google". There are lots of machine learning examples that learn from google like https://www.pyimagesearch.com/2017/12/04/how-to-create-a-deep-learning-dataset-using-google-images/
I think this depends on more than what you state here. In particular, it depends on what you intend to do with the data you analyze and how you intend to present it. If you copy/replicate/publish the material, then you need to deal with copyright as anyone would. But if you are only extracting naturally anonymous information from it you should have no problem. Your suggestion that you "reference" your dataset not by providing a copy of it, but by giving (with the date of access) the search terms that generate it, you should be fine. 

As an example, if you are researching how many people pass by a certain street corner on a given Tuesday, you can gather the counts without getting "informed consent" from everyone that passes. No issues there. But if you intend to publish, somehow, the names (or images, or other information) of those people then it is a completely different story. You will need to judge where on that spectrum your study lies. I think you can even categorize things in the aggregate as long as you don't label individual items with your categories. To say that "60% of the videos we examine have blue backgrounds" is benign. Even saying "40% of the videos in our sample present conservative positions" is fine, as long as you don't "name names" and point fingers. (I am not a lawyer, of course.)

If you were in the US, then your IRB would give you guidance on this. In your country there may be institutional rules to guide you. You should seek those out. But generally, the "academic use" exceptions to copyright that were in place in the past have been fading out as copyright holders try, usually successfully, to extend their control over the culture. Not a good thing, but the law can be used against you.