prospective studies found insufficient evidence to support an association between induced or spontaneous abortion and an increased risk of breast cancer. Politicization By the late 1980s, national politicians recognized that a focus on reducing access to abortion was not a winning political strategy. Some anti-abortion activists grew more aggressive and violent in the face of political abandonment, culminating with the murder of Dr. David Gunn in 1993 and the passage of the Freedom of Access to Clinic Entrances Act in 1994. With direct action discredited, anti-abortion organizations, including the National Right to Life Committee, came to the forefront of the movement. These focused on legal tactics, including lobbying against late-term abortions and access to mifepristone and demanding legislation based on the purported ABC link. More recently, anti-abortion organizations have turned to lobbying to increase obstacles to abortion, such as mandated counseling, waiting periods, and parental notification, and some feel that anti-abortion advocates treat ABC as simply another tactic in their campaign against abortion. There have been ongoing and incremental legal challenges to abortion in the United States by anti-abortion groups. In 2005, a Canadian anti-abortion organization put up billboards in Alberta with large pink ribbons and the statement: "Stop the Cover-Up", in reference to the ABC hypothesis. The Canadian Breast Cancer Foundation was concerned by the misrepresentation of the state of scientific knowledge on the subject. The continued focus on the ABC hypothesis by anti-abortion groups has fostered a confrontational political environment. Anti-abortion advocates and scientists alike have responded with criticisms. The claims by anti-abortion advocates are sometimes referred to as pseudoscience. During the late 1990s, several members of the United States Congress became involved in the ABC issue. In a 1998 hearing on cancer research, U.S. Representative Tom Coburn accused the National Cancer Institute of misleading the public by selectively releasing data. In 1999, shortly after the House debated FDA approval of the abortion drug mifepristone, U.S. Representative Dave Weldon wrote a "Dear Colleague" letter, enclosing an article from John Kindley. In it, Weldon expressed concern that the majority of studies indicated a possible ABC link and that politicization was "preventing vital information from being given to women." , abortion counseling materials in Alaska, Kansas, Mississippi, Oklahoma, and Texas incorrectly assert a possible link between abortion and breast cancer, while Minnesota materials correctly report no link. Similar legislation requiring notification has also been introduced in 14 other states. An