It's unbelievable -- but at the same time all too believable.
Do you remember the cannibal Albert Fish, who was electrocuted in 1936 for the murder of poor 10-year-old Grace Budd? After reading a "situation wanted" ad in the paper by a teenager who wanted a position "in the country," Fish wound up going to the apartment of the young man who'd posted it. Saying he would come back later to pick up the teenage boy to take him to his farm, he mentioned he was going to his niece's birthday party, then invited young Grace to join him. Her father let her go because they were poor and "she hadn't seen many good times." In short, they let her leave with a man they'd met only a couple of hours earlier. Fish wound up not only killing her, but also sending the family letters of how he'd cooked her body parts and ate them. When sentenced to death, Fish thanked the judge for allowing him to be executed, saying something to the effect of "this will be the biggest thrill yet."
Then there's the horrific story of Sylvia Likens, whose carny parents entrusted her care to one Gertrude Baniszewski while they traveled the carnival circuit in the early 1960's. Sylvia's father didn't even stick his head in the door of Baniszewski's rundown flat to see what the conditions were (there were only three spoons in the house when Sylvia was dropped off and only one! when she died), and over the next few months Sylvia was starved, beaten, sexually tortured, given scalding baths, and eventually died after teenage tormentors (with Baniszewski's encouragement) burned the message "I'm a prostitute and proud of it!" into her belly. After that diabolic event, Baniszewski tried to give Sylvia some crackers in the hope the food would keep her alive; Sylvia responded "Give it to the dog, it's hungrier than I am." She died later that day.
I realize this is gut-wrenching stuff, but the point I'm trying to make is that there are many people who are...well...stupid, and it's not a new trend. Thanks to the media and Internet, we hear about it much more frequently than before, but it's a case of "the more things change..."