Labor leaders were targeted by the espionage and sedition acts because they

demanded better conditions for workers, even during a war crisis

Explanation:

The Espionage Act of 1917 was enacted by Congress to curb any resentment for the war efforts, military prosecutions or the government during the period of World War One. The upgraded to the Sedition Act of 1918 for similar measures. Labor leaders became immediate targets. They were fined and sentenced to prison for their socialist priority over war crises. International Workers of the World have suffered so badly that it has never recovered. Radical labor leaders bore the burnt of repression.