In Virginia, the supervisors of Prince William County are considering a policy that "would require police to check the residency status of anyone suspected of breaking the law. And it would require schools, libraries and even swimming pools to verify the immigration status for anyone using county services." As this AP story suggests, this resolution might lead to a court challenge, since the courts have declared that "undocumented immigrants" have a right to public education. Still, it seems as though many of the supervisors seem inclined to support this measure.
The Washington Post draws attention to a significant element in the statute being considered in PWC--the "writ of mandamus":

But there is one exceptional item in the resolution, Kobach said -- a provision that would give legal residents "writ of mandamus" powers, which would allow them to sue Prince William if they suspect that a county agency has failed to comply with the resolution's aim of denying services and reporting violators. Muzaffar Chishti, director of the nonpartisan Migration Policy Institute's office at the New York University law school, said that particular measure is "as close to encouraging vigilante action as I have ever seen on paper."

It seems that many current lawsuits about "illegal immigration" have had "undocumented immigrants" or their advocates suing a county/city/state for access; this measure would, it seems, reverse that tendency and allow citizens to sue the county.
The supervisors will vote on the measure on Tuesday.