Last year (January 2010), the Supreme Court struck down that provision in the case of Citizens United v. Federal Election Commission on the grounds that it violated their first amendment rights to free speech. While there have been many laws and court decisions over the years that have treated corporations like people or citizens, Citizens United was never-the-less a landmark in overtly saying that the protections of the Bill of the Rights are explicitly applied to corporations as well as people.
Justice Stevens, in his dissenting opinion, wrote:
At bottom, the Court's opinion is thus a rejection of the common sense of the American people, who have recognized a need to prevent corporations from undermining self government since the founding... It is a strange time to repudiate that common sense.In the nearly two years since then, many have talked about the need to over-turn this decision. Part of that is the movement to amend the Constitution to be clear that corporations are not people, and are not entitled to the same rights and protections as persons, and that money is not speech!
To learn more about this movement, and add your name to the petition, see movetoamend.org