These chemicals are already illegal under straightforward interpretations of US law, but they're not illegal "enough" to prevent them from being sold online and shipped Fedex.

This seems like the kind of "illegal" that mostly matters if you hang a sign out your window and start doing business.

It's worth noting though that there's really no intellectually valid argument in support of mephedrone or MDAI or whatever-the-hell-else they're selling --- if you're going to make meth, cocaine, and LSD illegal, this stuff clearly should be too.

MDAI and MDAT seem to me to be particularly suitable drugs for therapy. Whenever you blanket ban a group of chemicals you also make research on medicinal use practically impossible.