Transmitting account numbers unsecured is never a good idea. Since you appear to be in CA, you might check State law. If you are opening accounts online, I am confused how that is done in a non-secure environment or at least your account opening disclosure are not delivered secured prior to the account actually being opened and why, if you need to deliver an account number, you will deliver it using a different method.
_________________________
The opinions expressed here should not be construed to be those of my employer:
PPDocs.com