They don´t need to double-check data with your local authorities, of course.. it´s all about compliance.. any serious ico should delete files inmidiatelly after review. The reason to do KYC is to prevent legal problems in countries where ICO are forbidden.. (guess if you run a popular ICO with no KYC and you land in the USA... you can  be inmediatelly charged with a legal crime.. and have to respond a few questions and maybe got charges for selling to potential USA investors.. otherwise KYC is a piece of mind for any company doing an ICO, to justify no USA/etc investor could purchase your "ilegal" product there cause you had a KYC process.)