Because the email tells employees to stop leaking information.
When it comes to leaked information, it's become easy to draw comparisons between Tesla and a pasta strainer given its past few months. We've seen leaked information about the Model Y prior to its reveal, and then the company's CEO Elon Musk had to face legal consequences for sharing too much inside information about Tesla on Twitter. Tesla, of course, would love if its employees would stop sending information meant for internal eyes only to the press, so its security team sent an email out warning them to stop leaking information or else.
Perhaps as retaliation towards Musk's supposedly abrasive style of leadership, a rogue Tesla employee leaked that very email to CNBC before several current Tesla employees (who requested to remain anonymous, of course) confirmed it.
The email warned employees that outsiders "will do anything to see us fail" and are "targeting" Tesla workers on social media. It goes on to remind employees that they signed a confidentiality agreement as part of their employment contract and that "Tesla will take action against those who improperly leak proprietary business information or violate the non-disclosure obligations to which we all agreed." Tesla went as far as to outline the actions it could take, which included, "termination of employment, claims for damages, and even criminal charges."
Despite the fact that someone was recently fired from Tesla after posting the phone number for an internal meeting to social media, it seems that nothing can deter employees from leaking information.
Seeing as this email was leaked in full, it doesn't look like Tesla has a handle on its hole-riddled ship. Even in the past few weeks, leaked information showed Tesla did not receive exemptions for Chinese components in the Model 3, was experiencing glitches in Model 3 production, had a strained relationship with its battery suppliers, and was taking long periods of time to complete vehicle repairs. In order to stop the leaks for good, Tesla will need to radically change its corporate culture and put in new measures to deter and prevent employees from leaking information...or else the short sellers will win this war.