Summary: "Slamming" and "cramming" are two common types of abuses involving telephone service today. Slamming occurs when a customer's telephone service is switched from one telephone company to another without his or her authorization. Cramming occurs when unauthorized charges are placed on a customer's telephone bill for services and products. Both state and federal agencies are taking regulatory and legal action against the perpetrators. This report describes the (1) number of complaints about slamming and cramming received by state and federal authorities, (2) types of protections implemented by state and federal authorities to increase consumers' ability to protect themselves against slamming and cramming, and (3) state and federal enforcement actions taken against slamming and cramming violations since 1996. GAO found that slamming continues to be a significant problem for consumers. From 1996 through 1998, state public utilities commissions saw the number of complaints about cramming rise from 20,741 to 39,688--a 91-percent increase. Complaints to state authorities about cramming rose from about 800 in 1996 to about 20,000 in 1998. State commissions were able to resolve about 60 percent of the slamming complaints they received in calendar year 1998. In addition, from 1996 through 1998, the commissions and attorneys general in 35 states reported completing 219 formal enforcement actions against companies or individuals for telephone slamming and cramming violations.