Amanda Bronstad in this article writes about the differences between the copyright infringement cases that ultimately doomed music file sharing sites like Napster and Grokster and the current batch of cases involving video sharing sites like YouTube.  On one side of the argument, video sharing sites say that a major percentage of their content is perfectly legitimate and legal.  Also, these sites, especially YouTube, point out that they remove content considered to be copyright infringing immediately after they are notified by the copyright holder.  This did not happen with music file sharing sites. However, lawyers for Hollywood's major studios say that their case is bolstered by the fact that they now have a precedent in MGM v. Grokster.  They argue that web sites know they make money off of this infringing material, and therefore are liable for induced infringement.  They also say that video sharing sites may be considered direct infringers because of the role these sites take in editing user content.

Bronstad also notes that while the recent agreements between YouTube and major studios such as Universal, Warner, and CBS does help legitimize the site, the agreements aren't necessarily "suit proof".  She says that many experts in the field see a major gray area that could be exploited by an ambitious company or law firm.  She says that the debate will ultimately come down to the DMCA's "safe harbor provision", and whether or not these video sites have put in place and enforced rules to protect themselves from future legal issues.  She says that the strongest safe harbor these companies have is the ability to remove copyright infringing material from their sites.  If sites continue to consistently remove copyright infringing content, as YouTube has done over the last few months, then these companies will have a strong legal foundation for their business models.