https://chroniclingamerica.loc.gov/lccn/sn83030214/1918-05-07/ed-1/seq-1/

The Senate passes a measure to outlaw the Wobblies (International Workers of the World) after a quick debate. Senators are unable to agree whether the measure would apply to organizations that support lynchings and/or other strike activity. Holding office in an outlawed organization results in a $5,000 fine and 10 years in prison.

Source: "Senate Passes bill to Outlaw I.W.W. After Brief Debate," New York Tribune, New York, New York, May 7, 1918. Page 1, Column 4.