Under 18 U.S.C. § 2511(2)(c), a person who is acting under
color
of law may intercept communications when he or she is a party to the
communication or when a communicating party consents to the interception.
Depending on the circumstances, consent may be express or implied in fact
from
surrounding circumstances indicating that the party knowingly agreed to the
surveillance. SeeUnited States v. Van Poyck, 77 F.3d 285,
292
(9th Cir.), cert. denied, 117 S. Ct. 276 (1996).