In the age of Facebook and Twitter, a new crime has hit America: "Sharpie parties," gatherings of revelers armed with "Sharpie" magic markers and lured by social media invitations to wreak havoc on foreclosed homes. Five years into the U.S. foreclosure crisis, Sharpie parties are a new form of blight on the landscape of boarded-up homes, brown lawns and abandoned streets. They are also the latest iteration of collective home-trashing spurred by social media. At least six Sharpie parties were reported in one California county in recent months, where invitations posted online drew scores to foreclosed homes. The partygoers are...