Tim Wu in this Slate article describes in detail the differences between YouTube and Napster and why he believes that YouTube has very solid legal footing. Wu simply says the YouTube has a safe harbor provision in the DMCA protecting them, while  He also describes the "Bell lobbyists" and how their efforts set the foundation for YouTube's seemingly successful business model. 

The Bell lobbyists, Wu writes, fought one of the greatest copyright struggles in history when it took on Hollywood over the liability of internet companies for copyright infringement.  Wu describes the clash of these two entities as "Frazier meeting Foreman", saying that the unstoppable force that was the Hollywood lobbying team finally met an immovable object in the Bell lobbyists.  Hollywood, on one side, wanted internet sites to be responsible for all content on their site, even if they were unaware of the infringing content.  The Bell lobbyists insisted that this was ludacris and fought against Hollywood's lobbyists with all their political might.  A stalemate insued, so a compromise was reached.  Wu writes that this compromise would later become Title II of the DMCA, which states that companies are protected by a "notice and takedown" system.  This means that all a site has to do to comply with copyright laws is take down infringing material at the request of the copyright holders.  Therefore, YouTube only needs to quickly takedown any material after notified to avoid legal issues. 

Wu does mention that this provision is not 100% "air-tight" noting that if YouTube knows there is infringing material on its site and fails to act, it may be liable in court for the infringement.  Wu then describes the difference between Napster and YouTube, saying that if the Internet were a red-light district, Napster would be the "pimp" and YouTube the "hotel".  He says that while Napster, like a pimp, is a means of getting illegal things and nothing else, YouTube is like the hotel in that they only "provides the space for people to do things, legal or not".

Brian P. Wilkner discusses in this article the effects of the Sony v. Universal and MGM v. Grokster on the newest batch of cases that will "pit mainstream, consumer-participation-oriented companies against copyright owners".  The article gives background information on both the Sony and Grokster cases and talks about the contributory liability doctrine, and how the Sony decision limited the power of this doctrine by stating that Sony's VCR had significant non-infringing uses.  On the other hand, it noted the Napster and Grokster cases which found each music file sharing company guilty of copyright infringement, and therefore were illegal.  Napster's fatal flaw, writes Wilkner, was the fact that they had a centralized indexing system that gave the creators of Napster too much knowledge of what was actually being shared on their website.  Grokster attempted to circumvent this problem by creating a decentralized index which "deprived their creators of any knowledge of infringing activity".  The Supreme Court ultimately ruled against them, saying that companies that distribute a device with clear intentions of promoting copyright infringement were illegal, and that Grokster's claim that they were unable to stop copyright infringement from taking place demonstrated an "unlawful objective".  One of the interesting tidbits about the Grokster case was that the court did not rule on the limits of the Sony decision, as many court observers thought they would.

Wilkner then goes on to talk about "inverse Grokster scenarios",  which he says will "pit content owners against legitimate organizations seeking to capitalize on the demand for interactivity".  Companies like Google, MySpace, and YouTube, he states, will not make statements or take actions to promote copyright infringement, but will maintain day-to-day operations with the knowledge that some copyright infringing content is being viewed or placed on their sites.  This is in direct contrast with Grokster, which claimed ignorance by stating it was unaware of any infringement taking place on its site.  The article ends with Wilkner proposing a "test" of the inverse Grokster dilemma in which the courts will have to decide whether the public benefit from these sites outweighs the property rights of copyright holders. 

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.