The Lawyers Weekly (of Canada) writes about free vs. paid online legal research tools:
Cost-conscious lawyers may ask themselves: Can we get by using only freely available research tools?
Chances are, the answer today is no. But free legal research tools continue to improve as new ones emerge and legal researchers everywhere are better off for them.
The low cost, easy accessibility and speed of popular search engines, particularly Google, makes them a natural destination for researchers of all stripes.
As the article points out, the paid services (in the U.S., that would primarily be Westlaw and LexisNexis) add very useful, human-created content, such as citation evaluation and headnotes that help researchers quickly and effectively evaluate case law. A newer, more reasonably priced competitor is Fastcase. It too is not dedicated to open access, but nonetheless increases access to case law due to its much lower prices and still-effective editorial content and categorization.
“Free” access is not quire the same as “open” access: open access, according to Paul George, is “the electronic publication of scholarly work that is available for free without copyright constraints other than attribution.” Free resources tend not to meet this level of copyright freedom in most spheres. Case law, however, essentially meets this requirement wherever you get it (at least, federal case law doesn’t – some states may attempt to limit distribution, although I doubt that such a restriction would hold up under close scrutiny), since you can use all the content (not including added editorial content, of course) with only a case cite as attribution.
For more on open access to law, read the Durham Statement on Open Access to Legal Scholarship, visit the 2006 Symposium on Open Access Publishing and the Future of Legal Scholarship from Lewis & Clark Law School, and the Open Access Law Program.
So where does one go to get free or open access to case law?
For Canadian legal research, I personally find CanLII to be highly useful and effective, and much prefer its search to Westlaw or LexisNexis (of course, there is less Canadian case law to search through than there is U.S. case law).
In the United States, AltLaw (drawing on freely available data stored at bulk.resource.org) provides access to a great deal of openly available federal . Content lags by several years, however, which makes it less useful for preparing actual briefs (not using one of the big two is almost malpractice currently). In fact, the content behind AltLaw is often much more readily found by searching Google, which indexes all of AltLaw’s content (as hosted by bulk.resource.org). Searches for case cites or case names often turns up results, if the case is old enough. In fact, Google is often successful even with more modern cases, either through links to Wikipedia or, especially with Supreme Court cases, directly to the case.
FindLaw provides free access to a great deal of up-to-date caselaw, but is in a delicate position since it is owned by the same company that owns Westlaw. While free, it is not focused on providing “open access” to research in the same way as AltLaw or CanLII. It is nonetheless quite effective at opening up legal research more generally.
Many of these U.S. resources focus primarily on federal law. State case law is much more difficult to find through open-access resources, and I still do not have a good source for general state legal research other than FindLaw.