Parents and children meet and clash on social-networking sites - WSJ.com

David Rivera recently had someone "unfriend" him on Facebook: His own child.

For months, Dr. Rivera, an obstetrician in Lombard, Ill., had been exasperated that his 25-year-old son, Nate, often complained he was broke and asked for money, yet posted photos of himself on Facebook taken at bars, restaurants, movies and concerts...