The USA possesses very restrictive rules regarding the funding of projects in order to make sure that the common man does not get pulled into some sort of pyramid scheme. Of course in practice this is just the result of looking towards private rich venture capital as the only people that should be funding projects, it really does create issues for crowdfunding though in practice it basically says not US no good.
https://www.sec.gov/news/pressrelease/2015-249.html