It's part of the national day of action for union members to get involved and get educated.
Bob Warnock, president of the local, is urging members to attend. In a message to members, he wrote
The Teamsters and all unions in America are working together to stop the assault on union members, middle-class families, ad workers in general....We cannot sit back and allow the rights we have worked so hard to gain to be stripped away.Learn more by going to the Teamsters 4.4.11 page here.