Perhaps I've explained it before, but we aggregate lists published by governments of "bad people" that other companies can then search via website, web services, or various batch reports to ensure that they are not doing any kind of business with said "bad people". But how often does this sort of thing make the news?

U.S. Links Iranian Bank To Fifth Avenue Building - washingtonpost.com:

Citing a series of alleged sham transactions and e-mails, Treasury and Justice write in court documents that Assa Corp., which holds the 40 percent interest, is a shell company that funnels the rental proceeds through a parent company in the Channel Islands, off the coast of France, to the Iranian bank, which is wholly owned by the Iranian government. Under various laws and presidential orders, the government of Iran and related entities are prohibited from doing business in the United States without a license from Treasury.

And yes, Assa Corp. is now designated "bad people".