I received five calls consecutively, one minute apart and they did not leave a message.  The numbers were odd:  650-755-60900 (twice), 755-60900 (twice), and one inbetween these two numbers that rang "Unavailable"... all at:  7:23pm, 7:24pm, 7:12pm, 7:26pm, and 7:27pm.  The oddest part is that they were blowing up my phone and the phone number was either too many digits or missing a digit.  I phoned my cell phone company, but they didn't offer any help....  I believe the calls were a scam.  Unfortunately I answered the first call and the person had an accent... I hung up.