1. picket lines
1. Faced with a threat by actors to boycott the ceremony rather than cross picket lines, the association and NBC were forced to adopt another approach for the ceremony.
2. The NFL has not had a labor shutdown since 1987 when replacement players crossed picket lines to play for three games.
3. Some of these people demonstrate on the street at the slightest provocation, and some even try to cross picket lines deliberately.
4. Its cast was to appear in the parade, but the costumes and props are locked behind the stagehands'picket lines.
5. The heavy penalty could force the union off the picket lines and back on the job.