What is the requirement for the judge's approval for a Pen register during exigent circumstances?

In exigent circumstances, the correct approach regarding a Pen register is that verbal approval from a judge is permissible, but it is critical that a formal order is obtained within 72 hours. This provision allows law enforcement to act quickly when immediate action is necessary due to urgent circumstances. The rationale behind this requirement is to balance the need for swift response to potential threats or emergencies with the legal safeguards that ensure oversight and accountability in governmental surveillance activities.

This procedure reflects an acknowledgment of the urgency that can arise in law enforcement situations, while still maintaining a system of checks and balances through the requirement for a subsequent judicial order. Verifying this order within the specified timeframe ensures that there is a legal framework governing the use of such surveillance tools, preventing misuse or overreach by authorities even in critical situations.