Section 2 cases typically involve the behavior of one firm, acting alone.

WSJ: Sherman Stirs: U.S. Revives Section 2 of the Antitrust Act

Section 1 largely addresses situations involving anticompetitive behavior of two or more entities working in concert.

WSJ: Sherman Stirs: U.S. Revives Section 2 of the Antitrust Act

Walid Bachir, section head-public domain at the park's management agency, thinks the sounds do help modulate behavior.

WSJ: A California City Is Into Tweeting��Chirping, Actually��in a Big Way