There are hidden reputation and anti-fraud mechanisms at play in a lot of consumer areas (incentives, reviews, etc.), it would be trivial to apply them to this too.
Most fraudulent activity isn't attacking competitors, as it's prohibitively expensive, but instead propping up their own reputation. i.e. Amazon's fake reviews are mostly five-stars.
For one or two attacks, sure, but at the scales to having impact we're talking prohibitively expensive, especially with antifraud detection whacking the moles.
Most fraudulent activity isn't attacking competitors, as it's prohibitively expensive, but instead propping up their own reputation. i.e. Amazon's fake reviews are mostly five-stars.