About 25 percent of telephone customers in Detroit and Grand Rapids have had their telephone service illegally switched to another company or know someone who has, according to a National Consumer League report published in the Detroit Free Press. Michigan ranked eighth in the country for complaints about the practice, known as slamming.
—Megan Defendis, "slamming rates high in Michigan," Crain's Detroit Business, October 37, 1997

AT&T is setting up a task force to probe incidents of what it calls "slamming" — a tactic the telecom giant says involves other common carriers (OCCs) appropriating AT&T long distance subscribers without the customer's consent.
—Mark A. Kellner, "AT&T to investigate 'slamming' cases," MIS Week, December 5, 1988