Filing IRS complaints against political non-profits

Opponents of Prop 8 have set up a blog here:

How to File an IRS 501(c)(3) Complaint

The LDS church, through inciting its members to donate time and means to support Proposition 8(resulting in millions of dollars of cash contributions from its members and countless volunteer hours), and in-kind campaign contributions to a group that supports Proposition 8, has now made a substantial part of its activities attempting to influence legislation.

Take your pick: free speech or tax-exempt status.