I've always felt a little uneasy about how cavalier production can be with SS numbers and personal info. Not just via email- but all the I-9 and W-9 forms and timecards on set. Not to mention some of the absurd start paperwork- the information within someone could use to take out a loan or apply for credit cards, etc. Who knows what PA's or others see all of that stuff. I don't think I've ever seen any of that paperwork kept in any kind of secure manner.