Sure thing! I never meant to use things illegally, I just wanted to make sure what is and what is not, since I see tons of movie reviews which made me think there are proper ways of using movie clips or screenshots. I think I'll be stuck with avoiding them
Sadly, there are two things at play here- both copyright law and Content ID.
Your use of their content may fall under fair use, but it would be up to a court to decide that...and, most importantly, would you be willing to hire a lawyer and go to trial over a video knowing that, if you were to lose, you would be forced to not only pay damages, but also for their lawyer and all court fees?
Secondly, Content ID is automatic and it happens as soon as you upload your video (doesn’t matter if it’s public or not)...and, because it’s automated, it doesn’t care if you’ve used the footage legally or not.
More often than not, no harm will come from Content ID...your video will show ads and they’ll collect all earnings from it, but your channel won’t have any issues and you won’t receive a strike.
That all said, stills are, by far, the safest way to go with reviews.