One example of a patent case in which the PI was not upheld on appeal is Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343 (Fed. Cir. 2001). Amazon sought and got a PI against Barnesandnoble.com preventing it from using their "one-click" check-out system.
The court of Appeals for the Federal Circuit concluded:
CONCLUSION
While it appears on the record before us that Amazon has carried its burden with respect to demonstrating the likelihood of success on infringement, it is also true that BN has raised substantial questions as to the validity of the '411 patent. For that reason, we must conclude that the necessary prerequisites for entry of a preliminary injunction are presently lacking. We therefore vacate the preliminary injunction and remand the case for further proceedings.