> Backers received an email from Kickstarter saying the Laser Razor was "in violation of our rule requiring working prototypes of physical products that are offered as rewards".

Interesting. Was this a recent policy change? Control VR never showed any working prototypes either, and their campaign was allowed (this was in 2014). Their demonstration video was later revealed to be using another company's significantly more expensive product ($10k+ vs the $600 pledge price), with zero modifications. They never demonstrated any prototypes of the product they were claiming to develop themselves, yet the campaign went through and now they have everyone's money (>$400k) without delivering.