Are people really so easily manipulated? Iranians are filmed chanting, and...?

...the media shows subtext which says they are chanting "Death to the America". Since no American outside of Iranian background speaks Farsi, they could be shouting " We love pies!", or "Ali Khameini likes bum love!" and the sheep would know no better. Or am I the only one who gets suspicious when I see Iranians protesting in Tehran shouting in Arabic and carrying placards that are written in English?