It’s true that courts can dismiss infringement cases where the alleged use is considered de minimis, which means it was so insignificant that the court would not decide on the case.
However, don’t let this trick you into believing you can copy a little bit of a copyright protected work and get away with it.
There is no magic amount of content or number of words that you can copy lawfully. The use of just six words could be considered a copyright violation. In one case, a four-second guitar riff was considered an infringement [Bridgeport Music v. Dimension Films, et al. 410 F. 3d 792 (6th Cir. 2005)].
There is no set rule on the quantity or quality of the content. Each case is decided on the facts in that case. If you copy someone else’s work, they may sue you for infringement, which can be very expensive to defend no matter the outcome.
Many other factors besides quantity are taken into consideration, so you should always consult with an intellectual property lawyer to ensure you are following the law.