In U.S. v. Kuchinski (9th Cir. 2006) 469 F.3d 853, the defendant "did not argue that he is not responsible for the possession of images of child pornography" "located in the computer's downloaded files and ... in its deleted files." (Id. at p. 856.) "We have declared that, 'in the electronic context, a person can receive and possess child pornography without downloading it, if he or she seeks it out and exercises dominion and control over it.' Thus, defendant properly concedes that he did knowingly receive and possess the ... images that he downloaded. But defendant was charged with receipt and possession of ... images, which appeared in his cache files (i.e., Deleted Temporary Internet Files). ... According to the evidence before the district court, when a person accesses a web page, his web browser will automatically download that page into his Active Temporary Internet Files, so that when the site is revisited the information will come up much more quickly than it would have if it had not been stored on the computer's own hard drive. When the Active Temporary Internet Files get too full, they spill excess saved information into the Deleted Temporary Internet Files. All of this goes on without any action (or even knowledge) of the computer user. A sophisticated user might know all of that, and might even access the files. But, according to the government expert, 'most sophisticated--or unsophisticated users don't even know that downloaded Web pages are on their computer.' ... 'The cache is a "system-protected" area, which the operating system tries to prevent users from accessing by displaying a warning that access involved an "unsafe" system-command.' A computer user, who knows what he is doing, can go forward and get access to the cache files anyway. In the case at hand, there was no evidence that defendant was sophisticated, that he tried to get access to the cache files, or that he even knew of the existence of the cache files. There is no question that the child pornography images were found on the computer's hard drive and that defendant possessed the computer itself. Also, there is no doubt that he had accessed the web page that had those images somewhere upon it, whether he actually saw the images or not. What is in question is whether it makes a difference that, as far as this record shows, defendant had no knowledge of the images that were simply in the cache files. It does. ... In U.S. v. Romm (9th Cir. 2006) 455 F.3d 990, 995-996, the evidence demonstrated that the defendant knew about the cache files and had actually taken steps to access and delete them. On appeal, he conceded knowledge, and contested dominion and control, but we rejected his arguments. In so doing, we opined that 'to possess the images in the cache, the defendant must, at a minimum, know that the unlawful images are stored on a disk or other tangible material in his possession.' We relied upon a case wherein the Tenth Circuit Court of Appeals had declared that the defendant was properly found guilty where he knew that child pornography images would be sent to his 'browser cache file and thus saved on his hard drive.' ... ... Where a defendant lacks knowledge about the cache files, and concomitantly lacks access to and control over those files, it is not proper to charge him with possession and control of the child pornography images located in those files, without some other indication of dominion and control over the images." (Id. at pp. 861-863.)