American workers are getting mad as hell -- and they're not taking it any more.

First in North Carolina:

In a move highly unusual for nonunion workers, more than 500 employees walked out yesterday at the Smithfield Packing Company’s hog-killing plant in Tar Heel, N.C., the largest pork-processing plant in the world.

Workers involved in the walkout said it was fueled by anger over Smithfield’s recent decision to fire several dozen immigrants who the company said had presented false Social Security numbers in applying for a job.

Several of the workers said their action had largely crippled production at the plant, which employs 5,500 people and slaughters 32,000 hogs a day. But Smithfield officials said production had merely been slowed a little.

The walkout coincided with a big push by the United Food and Commercial Workers to unionize the Smithfield employees in Tar Heel, about two-thirds of them Hispanic immigrants. A number of workers said the discontent stemmed not just from the recent firings but also from brusque treatment, the speed of the production line and widespread injuries.

“They were tired of the working conditions,” said Gene Bruskin, director of the union’s organizing drive. “They want a permanent solution to the problems there.”

And in Houston:

An early-evening demonstration by SEIU janitors blocked a downtown intersection for more than an hour Thursday, resulting in the arrests of about 40 union officials and janitors, most of whom were from out of town.

Traffic was backed up for several blocks as police rerouted commuters around the three-hour demonstration.

Since Oct. 23, janitors have marched in front of office buildings throughout Houston, blocked streets and invaded a Galleria-area office in to bring attention to their cause.

The Service Employees International Union represents about 5,300 janitors who make an average $5.30 an hour and want a boost in pay to $8.50 an hour and health care benefits from the city's five largest cleaning companies.

The union's website reports that workers' lives were endangered as mounted police use horses to break up the demonstration. An 83-year old female janitor hospitalized.

Smithfield has become notorious in recent years for the dangerous conditions in its plants and its illegal union busting tactics. Earlier this year, a federal court decided that Smithfield had repeatedly broken the law in fighting the UFCW's attempt to organize its pork-processing plant in Tar Heel, N.C. nine years ago. UFCW is trying to convince Smithfield to agree to "card check" recognition of the union, instead of the marred, company friendly NLRB elections that the company abused before.

The Houston janitors went on strike last month for higher pay, more guaranteed work hours and health insurance. The 5,300 janitors, who currently earn $5.50 per hour, were organized by the Service Employees International Union last year in what was the largest union organizing campaign in the South in years. The janitors want their wages raised to $8.50 an hour, along with longer hours and health insurance. Currently they earn the lowest wages and benefits of any major city in the United States, according to the union.