Real Estate

In most states, sellers of property and brokers representing them are not required to disclose the fact that a property is a stigmatized or psychologically-impacted property (one that has had some undesirable event occur on the premises, such as a murder, suicide, haunting, etc.).
Do you believe such disclosures should be required by law?  Do you consider events such as these to be material factors in making a buying decision?  Does Virginia law require property sellers or brokers to disclose such information?  Is disclosure of a prior HIV-positive tenant or meth manufacturer required to be disclosed?