A syndrome that happens to many young adults/teenagers on Facebook, where they become friends with their parents, grandparents, and/or many other older adults. These older people will comment anything and everything pushing their morals and religious beliefs and criticizing the younger one. This eventually leads to a significant drop in activity from the younger user to avoid having the old people comment on them.
With Facebook's security feature, one can now combat the effects of Oldbook by permanently blocking the older people from seeing their status updates. This doesn't, however, block them from seeing pictures and other activity.
Dan: Hey Mike, how come I haven't seen you on Facebook lately?
Mike: Ugh, my mom, grandma, and two aunts added me and turned the place into Oldbook.