I've Seen a Lot of ICO project which managed by manager yahoo that became Successful and some of them are now On going like Vehicle lifecly Blockchain, VLB token, some of them are already Listed in any exchange sites and makes the market rock (exaggerated but real), Most of that project is based From, Estonia, slovenia and  i can't name all, And I can't also answer What Tax as far as I know but I not 100% accurately is they pay tax when Listed on exchange Sites. There are also Many Project I can't named all which managed by yahoo. but Basically, Japan would Be the leading Country Where ICO is Legal, but still need to do some Research.