The biggest name one so far is the H3H3 trial. One that looks to be settled soon is Akilah Hughes suing Carl Benjamin (Sargon of Akkad), where all that Benjamin does is edit together two of Hughes videos with the only original addition being a new title. This is almost certainly going to go in favor of Sargon, yet YouTube's algorithms turned up to the nth degree would almost certainly have blocked it.
If you go outside of YouTube, fair use law in the United States is very broad. Just look at what Richard Prince does with others' art. 
edit: added links
Combining them is another, sharing them is another.
We basically have no concept of personal use in our
 if they were broadcast you can record but only for time-shifting, you can only watch once (alone!) and then are obliged to destroy the copy; you aren't allowed to format shift.
The lack of any remaining semblance of balance in copyright between the rights of the demos and media interests shows how badly distorted our Western democracies have become from representing the rights of people in general above the rights of the rich.
Though a price for this is that we pay a special tax on every storage device we purchase.
Not a western democracy, though.