David Yerushalmi has written the comprehensive explanation of what Shariah Finance is, and why it is a threat to free people. From his Law Offices' website:

In November 2007, the [1] Center for Security Policy retained the [2] Law Offices of David Yerushalmi to prepare a legal memorandum which examined the civil and criminal exposure of U.S. financial institutions involved in Shariah-compliant finance (SCF). This memorandum was shortened and published by the Utah Law Review in Vol. 2008, No. 3. You can access the article directly [3] here.

The article, "Shari’ah's 'Black Box”: Civil Liability And Criminal Exposure Surrounding Shari’ah-Compliant Finance," can be found in pdf form at that link. If you are at all interested in becoming informed on this all-important subject, this article is the single best resource.