ive recently found two sites that provide an incredible amount of information about soft money contributions, contributors, expenditures, linkages and political implications. an article at one--publicintegrity.org--provides analysis and evolution of the current laws. consider the following:
After the Republicans for Clean Air episode in 2000, Congress passed legislation requiring that 527 committees register with the IRS and report their finances on forms similar to those that federal candidates and committees file with the Federal Election Commission.
Because of their tax status, 527 committees offer some advantages to donors that aren't available to other political non-profits, including so-called social welfare organizations, known as 501(c)(4) organizations. Social welfare groups can conduct political activity, but it cannot be their primary goal, and contributions to such committees can be subject to other federal taxes, including the federal gift tax. But contributions to 527 committees are not subject to such taxes and the money can be used for nearly any political purpose save direct contributions to federal candidates.
There is one advantage that 501(c)(4) groups hold over 527 committees, from a donor's point of view: contributions are not disclosed anywhere. A 527 committee funded by the pharmaceutical industry, Citizens for Better Medicare, reorganized as a 501(c)(4) after Congress mandated disclosure. The committee's 527 filings before the switch show $8.9 million in spending, but only $55,000 in contributions, since most of the money was contributed before the disclosure bill became law.
for a list of the 2004 campaign major players, go here link and check out how many of those non-disclosed donor 501(c)(4) groups are listed.
there's one more thing worth considering. collecting, tracking and maintaining all this data is now a function of the irs. hopefully its going to eventually tie them up to the point where theyll have no time to mess with us 
