Received call 10:56 a.m. Oct 24 2014 to US Government phone (BB). Called it back and got busy three times, which does not normally occur with either a cell or land line that is in normal use, as unanswered calls on a normal line will typically roll to voicemail for a private user or an automated system for a business.
The Do Not Call List is a list of phone numbers where the owner doesn't want telemarketers to call and a law against calling those numbers. For a scammer its one more law to break.