Democrat Senator Joe Manchin is calling for an outright ban on bitcoin. In a letter sent to both Janet Yellen and U.S. regulators, Manchin described the digital currency as “unregulated and unstable.” The Senator is also concerned that the inherent structure of bitcoin attracts criminals who have used bitcoins to purchase guns and drugs.

Manchin also believes the volatility of bitcoin compounds the problems and cites the recent closure of the bitcoin exchange Mt.Gox as an example.

Manchin’s call for a ban follows recent comments from the Alabama Securities Commission and Texas Securities Board warning consumers about bitcoin. This new call for a ban is raising speculation that the Federal Reserve will soon release a statement on the use of cryptocurriences.