HRExecutive.com has published an HR Tech Insights article about the challenges of HR compliance, and exaggeration by HR vendors about their support of compliance.
As discussed in the article, it's challenging for vendors to support compliance because HR laws are vague, don't anticipate the use of technology, and don't anticipate administration by a vendor.
Here's an excerpt: "A well-informed lawyer for the employer and a well-informed lawyer for the vendor can have a perfectly cordial and painstaking discussion, and still decide to reach different interpretations."
And here's the article: http://hrexecutive.com/unraveling-the-hr-compliance-myth/.