Chiquita Banana - they are the renamed successor to United Fruit Company, a very evil corporation that oppressed Guatemala and other Central American counties. They used their immense money to corrupt and run the government, destroyed any public projects that would threaten their monopolies, and kept the population in poverty for a long, long time. And then, when Guatemala finally got enough votes to challenge their dominance, they whined to the US government, who organized a coup, overthrew the democratically-elected government of Guatemala, and installed a brutal dictatorship. This happened back in the 50's, and since then United Fruit changed its name and transformed in Chiquita Banana, but while their name has changed, they are still just as bad as ever--they expose their workers to highly dangerous conditions and in 2007 were caught hiring Columbian paramilitary groups listed on the terrorist watch list for company security purposes (and probably to brutalize workers and competitors into submission). It seems strange that such nastiness would be involved with something like bananas, but it's all true.
BP - even before the gulf oil spill there was reason to boycott BP. In many ways, you could say that BP is responsible for the entire war on terror, or at least for creating many of the conditions that lead to it. Early in the 20th century a company known as the Anglo-Iranian Oil Company (AIOC) acquired an insanely one-sided contract with the nation of Iran, a contract that had been negotiated even longer ago with someone else entirely. As Iran developed, it became clear that the conditions of the contract were becoming very harmful to the good of the country and its people, especially since they found that AIOC was using "creative accounting" to transfer most of its profits to its holdings in other countries so that Iran received only a tiny fraction in exchange for use of its resources. Iran pressed AIOC to renegotiate a fair deal, and were repeatedly squeezed by oil embargoes and the withholding of oil royalties. Finally, the people of Iran elected a leader who vowed to nationalize Iran's oil drilling, ending the strangehold of AIOC. So AIOC, in actually a nationalized company itself, owned by the British government, convinced the US to sponsor a coup in Iran. Again, a democratically elected leader was overthrown, and a brutal dictator--the Shah--was installed and propped up, despite his notorious human rights violations and unpopularity. He allowed AIOC to continue to plunder Iran with impunity. He humiliated and exiled Iran's religious leaders, and basically gave the Iranian people two choices: live as an oppressed people under his boot (backed by the full might of the US military), or side with the only people mean and crazy enough to try to overthrow him despite his US backing--that is, side with Iran's extreme religious leaders (like Ayatollah Komeini). In the 70's, Iranians decided to side with the crazies to win freedom from the Shah's US sponsored oppression. That is why Iran hates the US, and Iran is one of the main reasons for the War on Terror. The coup happened in 1953. In 1954 AIOC changed its name to British Petroleum.
Bayer - after the US FDA denied them permission to sell HIV-tainted medical products in the US (the products were made from HIV and Hepatitis C tainted blood and were known to be infectious), they went ahead and sold them in a number of other countries, despite the fact that they knew this would infect any who used the products with HIV. Sure enough, tens of thousands of people were infected with HIV and Hepatitis C.
