Easily circumvented
There are hundreds of email providers that are not located in the US or affiliated with any US company. I cannot see that anyone gains any advantage by sending or receiving emails via Google or any other US service provider. Therefore any moderately savvy person would not use Google to communicate anything that was even slightly naughty.
So after the US manages to catch all the stupid criminals, the more intelligent criminals will have less competition ...
Biting the hand that feeds IT
