A loose coalition of Democratic elected officials, shareholder activists and pension funds has flooded the Securities and Exchange Commission with calls to require publicly traded corporations to disclose to shareholders all of their political donations, a move that could transform the growing world of secret campaign spending

via S.E.C. Is Asked to Make Companies Disclose Donations - NYTimes.com.

For reformers disclosure laws are a favored method of combatting potential campaign corruption. I think it helps, but recent prosecutions and scandal seem to suggest it does not prevent it. The concerns about chilling speech are likely overblown. Years into disclosure requirements for individuals we continue to see more people participate in the system, not less.