Fastcase, under the leadership of the very-cool Ed Walters, has introduced a new citation-checking service that “uses algorithms to find negative citation history.” It’s called Bad Law Bot. This algorithm is enabled by, of all things, Bluebook signals! “The Bluebook requires that courts indicate negative history of cases cited within opinions.”
In comparison to services like KeyCite and Shepards, this system is entirely automated, and does not requires teams of librarians to manually check every citation.
Bad Law Bot finds negative citation history by taking all the cases that have cited Roberts and examining how they’ve cited to Roberts. If a court has negatively cited to Roberts, Bad Law Bot will link you to that case. Keep in mind that Bad Law Bot determines negative case history by using algorithms, and that it is not intended to be a complete replacement for a full editorial citator or for reading all later-citing cases. A red flag means that there’s likely negative treatment, since a court has said as much by their use of a negative citation, but no red flag does not necessarily mean that a case is still good law. If a case has been overturned but no court opinion has cited to it yet, Bad Law Bot won’t be able to find any citation signal information.
Earlier automated-citation services have not performed particularly well.
In our recent white paper “Are All Citators Created Equal,” we compared the citator services of Bloomberg Law, LexisNexis, WestLaw, Casemaker, Fastcase, and Google Scholar – looking for indications of how they displayed both negative and positive treatment of published and unpublished cases. In that side by side comparison, we found that Casemaker, Fastcase, and Google Scholar’s citators did not include unpublished cases so they did not let you know if a later published case had reversed or affirmed the unpublished case. While we found that “legal researchers can still use these databases [Casemaker, Fastcase, and Google Scholar] to learn if their cases are still good law by taking the extra step to run a search using the party names as keywords,” we recommended “NOT relying entirely on any of [those three].” We concluded that the paid services offered by Bloomberg Law, LexisNexis, and Westlaw provided the most comprehensive coverage of this information.
From what I’ve heard, Bad Law Bot is pretty accurate, and stacks up well against the human-powered versions.