Here's how it works: A marketing service sends junk mail, including information on a Canadian lottery, to Americans, and develops a contact list from those who respond, said Hillsborough sheriff's Detective Skip Pask. The marketers then sell the contact list to a criminal group in Canada that sets up a boiler room, or location stocked with dozens of phones and employees who do nothing but make calls to the United States.
—Amy Herdy, "Sweepstakes scam dupes elderly," St. Petersburg Times, April 4, 1998

A nationwide survey by the CFTC staff uncovered what Bagley described as "disturbing" evidence that diamonds as well as copper, foreign currencies and platinum are being sold fraudulently with fast sales pitches across the country.

Indeed, many of the same boiler room sales tactics that characterized the sale of London commodity options — and led to a ban on such trading that started yesterday — are being used to sell diamonds as investments, Bagley said.
—William H. Jones, "Agency Asks Action on Potential Diamond Swindles," The Washington Post, June 2, 1978