have received several call from this number.  Area Code - San Francisco CA.   left messages saying they are from the IRS and there is a matter that is extreemly urgent and don't ignore their call.  When i did call number, the first thing the lady asked was what was my case number and name of attorney. told her she may have the wrong person - I didn't give her my name (she never gave me hers when asked). Never said who she was calling for??  then asked to confirm/verify mistake by giving last 4digits of my SS.- told her she was crazy and should know better since you are the IRS.    cant do that she should know better She hung up on me.   what kind of scam is this???