For operational security reasons, the sweep should be conducted without alerting suspicion.  Whilst it is preferable to conduct a sweep outside of normal business hours, such as evenings or weekends, other operational considerations must be addressed.

For example, by setting up a fictitious but plausible meeting during business hours, an eavesdropper could be prompted to activate a range of devices which can then be detected by the sweep team.

Posted in: Technical Surveillance Counter Measures