From this:

ZAPOPAN, Mexico - The Mexican crowd hooted "The Star-Spangled Banner." It booed U.S. goals. It chanted "Osama! Osama! Osama!" as U.S. players left the field with a 2-0 victory.

And that was in a game against Canada on Thursday before just 1,500 people...

See also 'Anti-Americanism in L.A.' from 1998:

Why would about 91,000 of the 91,235 fans in the Coliseum on Sunday night act as though they hated the United States? Why would U.S. citizens and residents blow horns and boo loudly enough to drown out the U.S. national anthem? Why would those who attend U.S. schools and receive U.S. medical care feel it necessary to pelt any U.S. player running near the stands with water and beer?... What took place in the L.A. Coliseum was a two-hour orgy of anti-Americanism, an explosion of hatred against the United States...

And this, which also featured chants of "Osama":

Last month, another soccer match was held between the French and Algerian teams outside Paris. France's national anthem, the Marseillaise, was booed by 60,000. Spectators in corporate boxes were told to lock themselves in, as Algerians began to chant the name of Osama bin Laden. When youths ran onto the field waving Algerian flags, the stands erupted in wild cheering. Spectators fled...