For those who want to connect or reconnect with others, social-networking sites are a huge, glorious honeypot. But for those who are disconnecting, they can make things quite sticky. And as the age of online-social-network users creeps up, it overlaps more with the age of divorce-lawyer users, resulting in the kind of semipublic laundry-airing that can turn aggrieved spouses into enraged ones and friends into embarrassed spectators.