Want to know whether a company has been sued for patent, trademark or copyright infringement? Want to track new IP case filings in a particular jurisdiction? Who’s Suing Whom is a simple interface for searching information about IP cases filed in U.S. district courts for at least the last five years. A free basic search reveals the name, case number, court and filing date of matching cases. For $25, you can purchase the full docket report for the case. I have not tested this other than to run a few free searches, but it could prove to be handy for quick reference. The site is sponsored by InterLingua, a translation service provider specializing in IP cases.