The Philadelphia Inquirer reports an increase in land disputes in Pennsylvania. The disputes concern the practice of "title washing." "The legal issue at stake, known as 'title-washing,' may affect many properties that were acquired in the last century through tax sales. It is rooted in the court's interpretation of an 1804 law allowing counties that claimed undeveloped land for unpaid taxes to also retake title to the mineral rights, sometimes unbeknownst to the subsurface owner, who was not tax delinquent."
Thought you might be interested.