A former disgruntled employee who had access to my email provider deleted all the addresses? Any recourse?

First, I'm no computer expert, but all the computer experts I have dealt with tell me that it is very difficult to permanently delete anything, and they've often been able to retrieve information from a computer that the owner thought had been deleted.  A computer expert and/or your email provider may be able to retrieve the addresses, although it could be costly. Second, most, if not all, American jurisdictions laws making hacking a crime.  You may want to file charges. Finally, you also may have a civil suit.  Although it may be difficult for you to show any actual money damages, some claims don't require any.  In NY your claim would probably sound in the common law tort of prima facie tort, however I know that a lot of the common law has been codified in California.  You may have a claim for the violation of one or more California statutes.  For example, it might form the basis for an unfair trade practices claim.