Then, in 2014, he gained national notoriety when he was arrested after carrying an AR-15 through Phoenix Sky Harbor International Airport to demonstrate his legal right to carry a firearm.
"I must protest a now nearly institutionalized attempt to intimidate us into surrendering our civil rights to other people's irrational fears," he wrote in an opinion piece after charges against him were dropped.
Now, he faces even bigger scrutiny.
Late last month, Steinmetz and another man were federally indicted as part of an investigation into illegal bitcoin trading in Arizona.
60 bullets and $166,000
The other defendant in Steinmetz's case is Thomas Costanzo, a Mesa man who uses the online alias "Morpheus Titania."
In April, a multiagency task force raided Costanzo's Mesa home and found 60 rounds of ammunition, officials said. He is barred from possessing firearms due to a previous felony marijuana conviction.
In June, the pair were indicted on two counts of illegally operating a money-transmitting business without proper licensing.