In an analysis of the movement from traditional to electronic surveillance in both the public and private sectors, Gary Marx identified nine key characteristics of the new surveillance. Such systems are able to transcend time, darkness, distance, and physical barriers. They are capital, rather than labor, intensive. They target categorical, rather than, specific suspicions and are decentralized and trigger self-policing. They have low visibility; and finally, they are increasingly intensive and extensive, discovering larger amounts of previously inaccessible information. However, an analysis of criminal justice system use of electronic surveillance reveals that these generalizations may be misleading. Current monitoring devices have a number of limitations: durability is difficult to assess, they are not truly tamper-proof, environmental and other external factors may affect reliability, and their use is limited to individuals with a phone. While capital intensive, they are cost effective compared to other alternatives. Further, monitoring programs can be tailored to offer multiple levels and degrees of control that are suited to an individual offender's needs. While such monitoring programs appear to reduce violations, their overall effectiveness must be judged in terms of direct and lasting effects on offender behavior. Finally, constitutional issues related to the increasing use of electronic surveillance will have to be addressed. 2 tables, 4 figures, 7 notes, and 28 references.