Because the ADA does not specifically mention websites, it also does not outline standards for how organizations can make their websites accessible. However, the DOJ has frequently cited recommendations such as the Web Content Accessibility Guidelines (WCAG) 2.0 as acceptable metrics for accessibility. WCAG 2.0 includes many different criteria at three different “success levels” of accessibility, ranging from high-contrast color schemes to closed captions for video content.
UPDATE: Since writing this post in August 2017, several important changes have taken place in the laws regarding ADA compliance for websites. On December 26, 2017, the Department of Justice announced that they have withdrawn the Obama-era Advance Notice of Proposed Rulemaking mentioned in this article which intended to require ADA website compliance. The DOJ’s withdrawal announcement stated, “The Department will continue to assess whether specific technical standards are necessary and appropriate to assist covered entities with complying with the ADA.”

Spector v. Norwegian Cruise Line Ltd.[64] was a case that was decided by the United States Supreme Court in 2005. The defendant argued that as a vessel flying the flag of a foreign nation it was exempt from the requirements of the ADA. This argument was accepted by a federal court in Florida and, subsequently, the Fifth Circuit Court of Appeals. However, the U.S. Supreme Court reversed the ruling of the lower courts on the basis that Norwegian Cruise Lines was a business headquartered in the United States whose clients were predominantly Americans and, more importantly, operated out of port facilities throughout the United States. 
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