[Excerpt] The policy issues discussed here may be especially important to consider in the context of proposals to require most or all employers to participate in E-Verify or another electronic employment eligibility verification system. A mandatory system could arguably make it possible to identify many more unauthorized workers. At the same time, under such a system, any inaccuracies, inefficiencies, or privacy breaches that occurred could affect much larger numbers of employees and employers. Employer compliance under a mandatory system would seem to be a salient issue, especially since it has direct implications for other issues, notably discrimination. Employer burden may be another important consideration. It may be that a mandatory system would require new strategies to address these issues.