Even companies who are innocent, and don't have any damning evidence because they did nothing wrong, need policies like this. You can be innocent and someone c

Even companies who are innocent, and don't have any damning evidence because they did nothing wrong, need policies like this. You can be innocent and someone can still sue you, find the suspicious-sounding messages, and use them against you. Proving your innocence may cost money and reputation, not to mention that since the justice system is imperfect, there's always a chance that you can still lose the lawsuit. This is just the corporate equivalent of "if you're not guilty, you have nothing to hide". You damn well do have something to hide even if you're not guilty, and that's why companies train their employees this way.