DavidGilbert99 writes: "The rise of ghost sites and the murky underbelly of online advertising has been exposed after Spider IO revealed the Chameleon botnet has been costing advertisers $6 million each and every month. With little or no restriction or regulation on online ad exchanges, this is potentially just the tip of the iceberg." Link to Original Source
Computers are unreliable, but humans are even more unreliable.
Any system which depends on human reliability is unreliable.