Got the same message last night...message was to have my attorney call so I thought I would dial the number to see what business it was since caller ID said only the number.  Turns out that that number is now out of service!  Hope that is the end of it!  :)

?report the incident to the Treasury Inspector General for Tax Administration at 800-366-4484.
?You can also file a complaint with the Federal Trade Commission at FTC.gov. Add "IRS Telephone Scam" to the comments in your complaint.

Do consider maybe getting a call blocking device or phone.. You can google them and many are around $60.00 or so.

same as reported above from 661-759-2960.  same guy calling me from new number as of today 6/14/2014 - 213-261-0748

Caller states they work for the US Treasury Dept. and I need to contact them right away in regards to a legal matter. I called the IRS to question this matter and they replied that the Treasury office will not contact anyone regarding legal matters by phone. They also traced the number back to a fraudulent scam that has been going on to take peoples money.

I got a very disturbing call from 661-759-2960.  They said I needed to take down this number right away and ask for Robert Mathews.  He got very mean with me and said it was urgent.  I laughed and told him "no one tells me what to do" :)
Anyway, I told him never to call me again.  Weirdo

Thanks for alerting me!!

A man called insisting that I was going to jail someone was coming to my house in 45 mins. Claims I owed IRS which was a lie he didn't speak good english he call us about 3 times today. All a scam .. All he was doing is harrassing us about going to Jail. and I hung up on him,

Same, here just got a call.  He did not say US Treasury or IRS I don't think as I could barely understand the message.  But if definitely said legal department.  The message was worded in such an unprofessional way with vocabulary that a professional would not use but more like a high school kid would say.  "you are going to be in trouble" What professional person from a legal dept would use that terminology.  And the threats if I don't call him back.  Again unlikely to say this. Crazy.

Got same message: "Yew in Beeg trouble with Department of Treasury....meesgter Dwight...much leegal action for yew! Yew must call my boss at theese number....right away! I am paralegal Lee Boski...yew in Beeg trouble..."

I received two calls from this same number today. I never had any trouble in the past with the IRS and became nervous when I heard the threating message. I googled the IRS website and found the same public notice you posted
http://www.treasury.gov/tigta/press/press_tigta-2014-03.htm
I then googled the phone number and thankfully found that it must just be a scam.

I also received 3 calls on my answering machine from the same number. Same circumstances, heavy accent, US Treasury, threatening legal action and possible jail time. I had a tax issue resolved several years ago. I called the Treasury and was informed that they have no connection to this number. When they called again today I picked up and told him I called the IRS and was informed that he was a scammer. I informed him I was a retired cop and that he was going to jail if caught. I gave his number to the PD and IRS. He yelled at me and hung up the phone.

I've gotten a few calls from 661-759-2960.  The caller, who can barely speak English and sounds Filipino, identifies himself as Derek Graham, employee ID 768519, from the US Treasury legal enforcement department, warning me that a lawsuit is going to be filed against me and that I need to call 661-759-2960 and speak with his superior Robert Matthews. I've had IRS problems in the past, so the first time this guy called, I got spooked and asked to speak with someone who could speak English and got some gobbledygook answer.  He/they have left a couple of messages on my answering machine.  This morning really got me curious because "Graham" called me three times before 7AM.  I did Spokeo and Google searches and came up with nothing to go with the number except the town, Wasco, CA which has a prision.  I then Googled "US Treasury scams" and immediately found a notice dated March 20, 2014 about a scam exactly like the phone calls I was getting.  The notice said that 20,000 people have been scammed out of $1 Million by these b*****ds and that the IRS does not call people, they send letters (paper trail).

http://www.treasury.gov/tigta/press/press_tigta-2014-03.htm