Draft-card burning was a symbol of protest performed by thousands of young men in the United States and Australia in the 1960s and early 1970s. The first draft-card burners were American men taking part in the opposition to United States involvement in the Vietnam War. The first well-publicized protest was in December 1963, with a 22-year old conscientious objector, Eugene Keyes, setting fire to his card on Christmas Day in Champaign, Illinois. In May 1964, a larger demonstration, with about 50 people in Union Square, New York, was organized by the War Resisters League chaired by David McReynolds. By May 1965 it was happening with greater frequency around the US. To limit this kind of protest, in August 1965, the United States Congress enacted a law to broaden draft card violations to punish anyone who "knowingly destroys, knowingly mutilates" his draft card. Subsequently, 46 men were indicted for burning their draft cards at various rallies, and four major court cases were heard. One of them, United States v. O'Brien, was argued before the Supreme Court. The act of draft card burning was defended as a symbolic form of free speech, a constitutional right guaranteed by the First Amendment. The Supreme Court decided against the draft card burners; it determined that the federal law was justified and that it was unrelated to the freedom of speech. In Australia following the 1966 troop increases directed by Prime Minister Harold Holt, conscription notices were burned at mass demonstrations against Australian involvement in Vietnam. In June 1968, the government reacted by strengthening penalties for infractions of the Menzies Government 1964 National Service Act, including the burning of registration cards. War protest ceased in 1972 when Australia's new Labor government withdrew troops from Vietnam and abolished conscription. From 1965 to 1973, very few men in the US were convicted of burning their draft cards. Some 25,000 others went unpunished. Before 1965, the act of burning a draft card was already prohibited by US statute—the registrant was required to carry the card at all times, and any destruction of it was thus against the law. Also, it was entirely possible for a young man to destroy his draft card and still answer his country's call to service by appearing at an induction center and serving in the military, and it was possible for a registrant to faithfully keep his card on his person but fail to