People say this as if laws and rules didn’t work in the days of cash transactions.
I don't know why I have to keep explaining this, but cryptocurrencies can and will be regulated using exactly the same mechanism that basically everything else is.
The government makes some rules, asks you politely but firmly to follow them, observes carefully to see if and when you break them, and then beats you with a (usually, but not always, metaphorical) rubber hose until you choose to comply. Nothing about crypto interferes with this process, even theoretically.
Sorry, what? ICOs and other scammy behaviors _are entirely public_. A company visible to the public comes along and starts selling "coins"/"securities". How exactly is it that this can't be regulated? Just because it's crypto doesn't make it unregulatable, these are people in the real world doing bad things--not some opaque UUID in a digital ledger somewhere.
And let's suppose someone came up with a way of selling these coins anonymously online in a secure way. Guess what! Nobody would buy them, because why would you buy securities from an anonymous online source that could just as easily be a 13 year old writing the modern remake of the 1994 hit film _Blank Check_?
That's inherently the issue here. It's not a matter of sending money/value/currency/whatever anonymously. These are companies that are coming out in front of the public in the real world, talking a big crypto game, then disappearing into the void with millions of real dollars. Or perhaps not disappearing, and providing no value to the people that bought into the scheme (contrary to the advertising they used). Or any number of other things that the SEC would have something to say about.
Just because it's "crypto" doesn't mean that its intersection with the real world is free from scrutiny and the rules of the governments of our real world.