The record label plaintiffs in the Jammie Thomas case have moved in limine to exclude the testimony of Thomas' expert, University of Minnesota computer scientist Dr. Yongdae Kim, on the grounds that his "fourteen possible explanations" for how someone other than Thomas might be responsible for Thomas' alleged copyright infringement "lack any factual or scientific basis" and thus are inadmissible under Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993).
Motions to outright exclude an expert are notoriously difficult to win, because the judge's easy answer is: let the jury hear it, and you can cross-examine him all you want. But I do think this motion has a better-than-average chance of succeeding, given its persuasive argument that Kim offers only speculation as to what might have happened, rather than well-supported opinions as to what actually did happen, and that he lacks expertise in the workings of Kazaa.
Here's Kim's expert report, and that of plaintiffs' expert Dr. Doug Jacobson. And here's an earlier post by me about the expert reports, and an article by Ars Technica's Nate Anderson.