Faculty have a total right to control what happens in the classroom. If a faculty member says "lids closed", then her students should close their laptops. The minute faculty lose the ability to control the behavior in the classroom is the point at which teaching and learning effectiveness stops. With this authority, however, comes the responsibility to use it wisely.
A total ban on laptops is a bad idea because laptops can be a marvelous learning tool within the classroom. There are many instances where having your students utilize their laptops will accomplish the active learning that faculty would like to promote. Students want to use their laptops, and you can turn this desire into opportunities for learning.