If the RIAA can't stop music sharing, the U.S. government is going to have an even harder time trying to stop the sharing of federal court documents hidden behind a paywall. Those documents aren't protected by copyright law.
The PACER service provides on-line access to U.S. Appellate, District, and Bankruptcy court records and documents. The fee to access PACER is $0.08 per page: "The per page charge applies to the number of pages that results from any search, including a search that yields no matches (one page for no matches.) The charge applies whether or not pages are printed, viewed, or downloaded." For people who do a lot of legal research, those fees add up quickly.
Enter RECAP, a Firefox add-on created by a group of people at Princeton's Center for Information Technology. Install the add-on and any documents you access on PACER are automatically uploaded to an Internet Archive repository. These documents are then shared with other users when they do similar searches. See a video overview of how it all works here. The repository already has over one million documents available for free download.
Is this legal? It sure is. The PACER site says "The information gathered from the PACER system is a matter of public record and may be reproduced without permission." There's no copyright on these documents.
PACER also says "Any attempt to collect data from PACER in a manner which avoids billing is strictly prohibited and may result in criminal prosecution or civil action." Technically, though, the data isn't being collected from PACER by RECAP users, although they are using the site as a search engine of sorts.
Harlan Yu, one of the creators, blogs about the project here.