What gives? It's a message from workers that they have finally had enough, labor experts say.

Having endured a deep recession, when their jobs were imperiled and their low wages remained unchanged, workers have been under tremendous stress.

...

"There's more of an awakening and more self-assertion," said William Gould IV, who chaired the National Labor Relations Board under President Clinton and is now a law professor at Stanford University. "That's going to continue."