Some places like Amazon and Newegg are moving to models that require you to have purchased the item through them to review it, which addresses your issue. Howe

Some places like Amazon and Newegg are moving to models that require you to have purchased the item through them to review it, which addresses your issue. However, as long as reviews are accepted without proof of purchase, what else can companies do? Sue for slander? That's also endless whackamole.