There is no set length of copyrighted video that can be used without infringing on copyright laws. The determination of whether the use of a copyrighted work is considered fair use depends on a number of factors, including the purpose and character of the use, the nature of the copyrighted work, the amount and substantiality of the portion used, and the effect of the use upon the potential market for or value of the copyrighted work. In general, uses that are for purposes such as criticism, commentary, news reporting, teaching, scholarship, or research are more likely to be considered fair use. Uses that harm the copyright owner's ability to profit from their original work are less likely to be considered fair use. It is ultimately up to a court to determine whether a particular use of a copyrighted work is fair use.