Basically Namecheap should remove their account for "electrumdiamond.org". But it seems to be difficult to contact the Namecheap support at all.
If reported to the the law enforcement agencies why are the domain and Git still active?
Probably because they're too small of a fish to dedicate law enforcement resources to. This is unfortunately pretty common with internet crime. Don't expect the feds to do anything if you haven't lost significant amounts. (Although in this case, it does seem pretty significant)
It's really up to github to keep removing these projects really, which can be quite difficult if they just keep popping back up under new accounts.