According to Morello's social activism Web site, Axis of Justice, he was one of about 400 protesters arrested during a march last Thursday to raise awareness for immigrant hotel workers' rights.
He was charged with unlawful assembly for refusing to move from the main entry road into Los Angeles International Airport.
Morello, 42, spent the evening in lockup and was released Friday morning. "Bail was high," he said — each arrestee had to pay $5,000. But, he added, "spirits were higher. We had a rousing civil rights-era-like hootenanny on 'the inside.' "
In 2005, Audioslave played a free show in Cuba. It was the first American rock group to perform in that country in 26 years.
"Revelations," the band's latest album, was released last month.