CHICAGO — Nearly 100 teens marched outside Chicago police headquarters Thursday night to protest the department''s plans to equip officers with semi-automatic rifles, saying the weapons could make the streets more dangerous. Carrying signs like "Stop the War on Youth," teens said they didn''t trust police with the high-powered weapons and worried gangs would be encouraged to bolster their own arsenals. "The only people who need these guns are in Iraq," said Arthur McGraw, 19, an organizer with the nonprofit Southwest Youth Collaborative, which organized the rally. "It''ll shoot through brick, car doors. Say your family is in the house...