Fair use
Fair use is the US doctrine that allows limited, unlicensed use of copyrighted work for purposes such as criticism, news, teaching or parody.
Four factors
Purpose and character of the use, nature of the work, amount used, and effect on the market.
Why it matters
Commentary using short clips can resist takedowns on fair use grounds. The UK and EU instead have narrower listed exceptions such as quotation and news reporting.
Frequently asked questions
Is giving credit enough?
No; attribution alone does not make use lawful.