Could get very expensive very quickly.
Forty-eight US states regulate money transmitters although the laws vary from one state to the other.[3] Most of the states[4] require a surety bond with widely ranging amounts from as little as $25,000 to over $1 million and maintaining a minimum capital requirement. There is an association of state regulators, the Money Transfer Regulators Association (MTRA)[5] that seeks to create uniformity and common practices and efficient and effective regulation of money transmission industry in the United States of America. The MTRA membership consists of state regulatory authorities in charge of regulating money transmitters and sellers of traveler’s checks, money orders, drafts and other money instruments.
I had to help write a feasibility report on this at CEX: ( you don't have to have a service offering in every state, and it's certain states that have a long history of financial regulation, that make up the bulk of the surety. Like New York and California. Some states are damn near freebies, inversely. The capital requirement is pooled, that is, there are only a few times where the state requires their capital requirement to stand alone, for liabilities sake (again, Cali, New York). Ultimately we hired a company to do this for us
This is gatekeeper regulation; allowing citizens to run exchanges without oversight is dangerous from a liability standpoint. And without the AML/KYC (my part of that report), an exchange is facilitating money laundering, as per the law. The US gov does not fuck around with KYC/AML.
It's a neccesity, the regulations, but I do agree it's limiting.