Intellectual property cases often require extensive up-front investigation. California trade secret plaintiffs must identify misappropriated secrets with "reasonable particularity" before commencing discovery, and plaintiffs in patent cases must often identify preliminary infringement contentions at the outset of the case. To help analyze the strength of IP cases, and to obtain evidence of infringement, lawyers frequently retain private investigators. Others do so to avoid the agony of trying to enforce discovery requests.
While the need for early investigation in many IP cases is clear, the ethical limits on the use of private investigators are sometimes ill defined. The controversy surrounding the widely reported Hewlett Packard investigation — and the role played by lawyers in that matter — raised broader questions about the ethical limits on the use of private investigators by attorneys.
The following hypothetical illustrates some of the unsettled issues raised by the use of investigators. Your client, a software company, has heard rumors that a group of former employees have created a new company and are selling a "knock off" of your client’s flagship product. Your client is concerned that its new rival has infringed its copyrights and misappropriated trade secrets. Word on the street also has it that the new company is infringing your client’s trademarks, falsely identifying the new software as the "next version" of your client’s product. Your client has sent a threatening letter, demanding assurances and access to the competing product. The response — from an outside lawyer — tells your client to pound sand. Your client has asked you to investigate potential trade secret misappropriation in the product, and to find out whether the competitor is engaged in trademark infringement.
One frequently used investigative technique in such cases is to have an investigator go "undercover," typically by posing as a customer. In this hypothetical, an undercover "customer" might be given infringing marketing material, and potentially purchase or obtain an evaluation copy of the product itself. While this technique does not involve the controversial issue of "pretexting" to gain personal information, it potentially implicates ethical prohibitions on the use of deceptive conduct and attorney contact with represented parties.

