What do you think of Zenefits security?

Just learned about a free online HR/Payroll management startup called Zenefits.com. Free is good (Spiceworks is free :)). I'm concerned about security though, since they handle names, email, birthday, social security and financial information.

Apparently they are getting quite a good amount of venture capital 66.5 million according to WSJ.

Would you use Zenefits? If so, why? If not, why not?

Here is the Privacy page:https://secure.zenefits.com/privacysee the Security section.

And their TOS:https://secure.zenefits.com/tosspecially the Disclaimer of Warranties.

Thank you!