Ditto.com (formerly known as Arriba Soft) was an early image search engine similar to Google's Image Search. So for example by entering "sailboat" into the Ditto website the searcher would be shown a selection of images of sailboats from around the Web. Ditto both presented the images in reduced form known as thumbnails and also provided links that would allow the searcher to open the full-size image in a new web browser window.
Ditto was sued by Les Kelly a photographer after Kelly discovered that Ditto had indexed his own website and the images found there. Ditto.com prevailed before the trial court but suffered a defeat on appeal before the Ninth Circuit in San Francisco. Although the Ninth Circuit found that Ditto.com's use of thumbnail images was allowed under the copyright law doctrine of "fair use " it held Ditto.com liable for infringement of the public display right for opening a new window to display the image. This technique is known as "in-line linking" or "framing" and is commonly used by numerous other Web search engines including Lycos Google and Altavista. By concluding that these common linking techniques infringe copyright law the Ninth Circuit seriously threatened linking on the Web.
Responding to the Ninth Circuit's initial ruling EFF filed an amicus brief on Ditto.com's behalf asking the Ninth Circuit to reconsider its decision. The Ninth Circuit subsequently issued a revised ruling in which it withdrew the portion of the opinion dealing with in-line linking and the public display right. The fair use ruling remained intact -- in other words the Ninth Circuit turned a potentially dangerous precedent for the Internet into a complete victory for fair use!
The Ninth Circuit later revisited the question of whether in-line linking infringes the public display right in Perfect 10 v. Google a case involving Google's Image Search. EFF participated as amicus in that case on this issue revisiting the arguments first made in Kelly v. Arriba Soft and the court ultimately held that in-line linking to images does not violate the public display right.