This act limits the use of injunctions to prevent only those strikes which are likely to become violent.

This act limits the use of injunctions to prevent only those strikes which are likely to become violent. Norris-LaGuardia Act. The Norris-LaGuardia Act banned all yellow-dog contracts. They stop the federal courts from being able to issue injunctions against nonviolent labor disputes. Their goal was to create a noninterference against workers joining trade unions. 

The answer would be hard press.