Wal-Mart workers are preparing to take part in a series of demonstrations outside stores on Black Friday, the biggest shopping day of the year.

A union-backed employee coalition called Making Change at Wal-Mart and OUR Wal Mart is organizing the effort, which includes a 1,000-store protest in Chicago, Dallas, Miami, Oklahoma, Louisiana, Milwaukee, Los Angeles, Minnesota, and Washington, D.C.

Part of the complaints come from workers saying that their health care costs are increasing, for jobs where the pay is so low, even the smallest decrease in take-home pay could create huge problems.

Wal Mart, despite the recession, is doing well financially, so that's creating a lot of worker discontent. However, protest organizers have not disclosed how many people are involved in the demonstration. Wal-Mart is the largest employer in the world, an analysts predict those participating will likely be just a small fraction of the company's workforce. 

Wal-Mart Stores files a complaint with the National Labor Relations Board hoping to prevent the demonstrations from taking place.