Liebert Corp. v. Mazur, 827 N.E.2d 909 (Ill. Ct. App. 2005).
The plaintiffs sought to enjoin several of its former employees from allegedly using electronic "e-commerce" Web sites - containing confidential customer lists, quotations and price books - in a new, competing business. One of the defendants admitted that he downloaded price books from the company's server to his laptop on the day he resigned. The plaintiffs hired a computer forensic expert to examine the laptop, and the expert discovered confidential files were accessed, downloaded, and placed in a Zip file. The expert also determined a new Zip folder - containing quote histories and budgets - was created and subsequently copied from the hard drive to a CD-Rom on the same day the defendant was served with the plaintiffs' complaint and preliminary injunction motion. During the copy, the computer automatically placed the files in a "CD burning folder," a folder most computer users are not aware exists. During the next few days, in a "mass wave of deletion," over 12,000 files were deleted from the defendant's computer. The laptop's application log, which tracks programs like the CD-Rom burning program, was also deleted four days after the complaint was served. Despite this evidence, the trial court denied the plaintiff's motion for a preliminary injunction, finding insufficient evidence existed to prove any of the defendants used the price books before they were destroyed. On appeal, the court reversed the decision, determining the trial court abused its discretion, and ordered the trial court to grant a reasonable preliminary injunction. The appellate court noted, "[b]ecause [the defendant] destroyed this crucial piece of evidence [the application log], we presume it would have showed he successfully copied the price books on a CD."