Who will fight? Whom have you referred? Aren't you one of them? The first fight should be started by ourselves. And people are fighting. Have a look on reputation thread. ICOEthics has already busted a lot of ICOs. Some other people also doing the same.
This is more like question what to do after everything is over. Prevention is better before than it happen of course, but what if it happens, you can't stop it then.
It's useless to report to the authorities about ICO fraud because the officers will not take action against your report because crypto is not regulated by any party so that all risks are borne by each person.
This is very bad assumption, every country has cyber crime division, they won't take action against anonymous and unknown people for obvious reason, but if people who run ICO and exit are known, once reported action will be taken against them.