The number called my cell 3-24-17 @ 9:24AM; it shows as a Missed Call. No voicemail was left & it shows on my phone as a Pacifica, CA originating # but news & FCC & FBI reports escalated their warning of scam calls to WARN people to never say "YES" in reply to ANY call received unless you 100% know the caller since the 'scam' call will record your voice (if you say "YES") and caller then is able to make calls to places, using your personal information and asked a question they play YOUR VOICE saying "YES" which on their originated calls to your personal banking, credit cards, etc they are somehow able to empty bank accounts and do other financial harms that wipeout call recipient's entire finances and destroy other aspects of one's personal life. TV news warning was on TV news again last night 3-27-17. EXTRA warning here may or may not apply to this caller as it leaves no message. Using *57, on Verizon Wireless's network was supposed to initiate a call trace, but it did not work. My elderly mother lives with us and she FREQUENTLY answers the phone and I have caught her engaging with unknown calling scammers, thus I am emphasizing this recent scam warning hoping people will share this warning to anyone who may inadvertently ANSWER calls by saying, "YES" instead of "HELLO" and anyone who could easily say this now devastating 3 letter word. NEVER say "YES" to any unknown caller!