; or (II) an immediate threat to national security; and (ii) requires the access or use of an electronic communications device to acquire geolocation information before an order authorizing the acquisition may, with due diligence, be obtained; and (B) in circumstances in which geolocation information may be used as evidence of a crime or in furtherance of a criminal investigation, there are grounds upon which an order could be entered under this section to authorize the accessing or use of an electronic communications device to acquire geolocation information. (2) Notice, order and termination If an investigative or law enforcement officer accesses or uses an electronic communications device to acquire geolocation information under paragraph (1)— (A) the officer shall, not later than 10 business days after acquiring geolocation information, serve upon, or deliver to by registered or first-class mail, electronic mail, or other means reasonably calculated to be effective, notice to the owner or authorized user of the electronic communications device whose geolocation information was acquired that such information was obtained or accessed pursuant to the emergency provisions under this subsection and describing the factual bases that led to the officer’s determination that an emergency situation existed; (B) in circumstances in which geolocation information may be used as evidence of a crime or in furtherance of a criminal investigation, not later than 48 hours after the activity to acquire or access the geolocation information has occurred, or begins to occur, the investigative or law enforcement officer shall seek a warrant or order described in subsection (b) approving the acquisition; and (C) unless a warrant or order described in subsection (b) is issued approving the acquisition, the activity to acquire the geolocation information shall terminate immediately at the earlier of the time— (i) the information sought is obtained; (ii) the application for the warrant or order is denied