Where do I send complaints about the activities/operations of tax-exempt organizations?

If you believe that the activities or operations of a tax-exempt
organization are inconsistent with its tax-exempt status, you may
file a complaint with the Exempt Organizations Examination Division, at the
following address:

IRS EO Classification
Mail Code 4910
1100 Commerce Street
Dallas, TX 75242

You may also use Form 13909, Tax-Exempt Organization Complaint (Referral) Form, for this purpose.   The complaint should contain all relevant facts concerning the alleged violation of tax law.

The IRS cannot advise you of any action it has taken or may take in response to a complaint. The confidentiality and disclosure provisions of the Internal Revenue
Code preclude the Service from discussing matters relating to any activity it might undertake regarding the tax-exempt status of an entity with anyone other than the principal officers or authorized representatives of that entity. These provisions were enacted by Congress to protect the privacy of all taxpayers.

The IRS maintains an active examination program to ensure that tax-exempt organizations, as well as taxpayers, meet the requirements imposed on them by the Internal Revenue Code.

Source:  http://www.irs.gov/charities/article/0,,id=139029,00.html

DISCLAIMER: This information is not intended to provide legal or
accounting advice, or to address specific situations. Please consult with
your legal or tax advisor to supplement and verify what you learn here.