I understood that that was your concern. In this day of scams and pfishing I am more concerned about the deliberate and blatant attempt to deceive. I'm sure you have firewalls on your machine, I feel sure the companies have firewalls on their machines, we have moved somewhat beyond the Wild Wild West that was the early internet years. My concerns have moved more to providing the wolf with a meal on a platter than the possibility to snatch a mouthful.
I have never bothered with an EIN, even though they are available at no cost because I am not convinced that they are that much safer. Certainly an EIN does not have a date of birth or mother's maiden name attached, but it can be compromised as well. Credit can be established for an EIN and abused, etc. It may be more difficult to do, but it can be done.
If you are deeply concerned about identity theft, there is insurance against it that would appear to cost about $75 a year that would probably be deductible as a business expense if you pose the reason for having it as "I am at risk because in order to work I must sign up with unknown companies, with unknown employees, frequently at unsecure internet websites." My bank offers such insurance, there is some outfit that has been advertising it on TV that is offering it through AAA or directly, etc. It is the current "in" thing.