Two conflicts of employer property rights vs the rights of employees have come up in different places, but with similar questions of priority and principle. In both cases employers have taken what is a legally and morally untenable position that their right to control their property is a superior consideration to the rights of their employees while on that property.
In Tennessee the "Guns in Trunks" bill makes it illegal for an employer to terminate or discipline a state-licensed Conceal and Carry permit holder for keeping a gun in their vehicle on company property. The essence of the law is that the permit holder's right of self defense should not be compromised throughout the entire day, nor their job endangered, because they spend part of that day on the property of an employer with a no-guns policy. The Tennessee Chamber of Commerce and gun-control advocates have opposed the law on the basis of safety.
Those policies, just so you know, have exceptionally little to do with safety: they are about liability protection for the employer. I've written several handbooks and you can trust me on this.
The other property rights issue comes out of my Church, as the United States Council of Catholic Bishops (USCCB) opposes the Health Care Reform law's contraceptive mandate. They have chosen to fight the law in court, not just based upon religious conscience, but on the basis of private property rights. Their theory is that Catholic workplaces such as hospitals, schools, and clinics, are private property. It is, in their view, an offense against religious liberty that their funds on their property have to fund something they find to be morally wrong.
The problem is that these institutions (1) are open to the public and (2) hire non-Catholic employees and (3) take federal Medicare and Medicaid reimbursements drawn largely from non-Catholic taxpayers. How you apply controls assigned to "private property" to those facilities and circumstances is anyone's guess.
To believe the claims in either of these examples is to accept the position that a landowner's right to control his or her own property extends to an ability to control the non-work personal conduct of all who set foot on that property. As an employer that is clearly and overreach. In the case of the USCCB, accepting their position extends their right of control past their property lines and into the private reproductive choices of their employees.
Just for clarity, stepping away from the employer/employee context momentarily, I would totally support the USCCB if those facilities accepted no public funds and hired only Catholics. Once you step into the public arena and accept public funds the rules change.
People are more important than property. As such individual rights should always trump property rights, lest the individual become on the level with and synonymous with property. As these conflicts wind their way through courts and legislatures, look for the law to eventually uphold that concept. The alternative is a plantation mentality that is contrary to our American ideals.