Five stars, zero clue: Fighting the ‘scourge’ of fake online reviews

Oobah Butler knew it was wrong to write fake online reviews for restaurants where he had never dined.

But he was 21, broke and living in his parents' house in Feckenham, an English village 115 miles northwest of London. A faceless vendor on a website that advertised freelance work offered to pay him 10 pounds (about $15 at the time) for each review he wrote and posted on the travel site Tripadvisor.

The job was simple. He would receive an email with the restaurant's name. Then he would log into one of the four or five profiles he had set up on Tripadvisor to avoid suspicion, look at pictures of the restaurant's food and study the menu.

The reviews were always positive (raving was a job requirement) and "verbose," he said.

One post said a waiter was so attentive he should get a raise. Another said something along the lines of "this place has one of the...