They need to create new regulation, not cack-handidly apply old regs to entirely different technology
A lack of precedent makes this the biggest challenge. New regulation would have the same problems.
Personally i don't think that ICOs should be banned or regulated - if anything, they are frequently done by anonymous or fake identity people and cashed out using monero, anyway.
Just explain people that they are a scam, and a crime if (unlikely) caught, just like they explained about nigerian prince scam.