...migrant workers who harvest fruit and produce each year in Florida and across the nation...won what many consider a big victory...[when] their nearly four-year boycott of Taco Bell [part of Yum!] ended with one of the nation's largest fast-food chains agreeing to pay a penny-per-pound increase to nearly 1,000 workers who harvest tomatoes...The Immokalee activists now have launched the second phase of their campaign, with letter-writing barrages aimed at enlisting McDonald's, Burger King and Subway in the reforms...