@gungasnake,
" Down with USA" doesn't mean "Down with American people" or things like that. Also this slogan mainly is used by Iranians (not by all Muslims) and comes from dark history of America's imperialism and intervention in their country.
On 1980, after the success of Iranian 1979 revolution, when US government saw itself unable to stop the revolution, they provoked Saddam Hussain to invade Iran. A war that resulted in hundreds of thousands of casualties.
Later, they invade Iraq and ousted and killed Saddam Hussain.. Once their full support was behind him and years later, when no longer he was serving their purposes, he became a terrorist...
I think it's better to say "Down with double standards" that result in bloodshed of innocent people.