If your employer accuses you of hacking into the company’s computing system and perpetrating a fraud, and you happen to be guilty, what is your safest tactic if you want to escape criminal charges? The answer is: Ask them to prove it. One out of three times, even if computer forensics experts are brought in and given unfettered access to all systems, it will be impossible to prove who is guilty of what. The reason is that few computer networks maintain comprehensive audit trails of who did what and when…