Unfortunately, the IRS can take a lot  of aggressive actions to collect money from taxpayers. As this article  from Examiner.com explains the IRS can even issue summons to collect  information pertaining to your tax liability.
Under the Internal Revenue Code §  7602, the IRS has the authority to issue summonses: “For the purpose  of ascertaining the correctness of any return, making a return where  none has been made, determining the liability of any person for any  internal revenue tax or the liability at law or in equity of any transferee  or fiduciary of any person in respect of any internal revenue tax, or  collecting any such liability.”
The IRS may issue summonses for testimony,  records (“books, paper”), or “other data which may be relevant  or material to such inquiry.” They may not, however, make unreasonable  demands of taxpayers.
Under § 7609, the IRS may issue  summonses to third-parties, for example to the taxpayer’s bank. However,  the taxpayer must be notified before issuance of such a summons, and  retains the right to request that the party not comply with the summons  unless it is ordered to do so by a court.
Taxpayers receiving such a summons have  20 days to ask a federal district court to quash the summons. In such  a case, the IRS may seek to compel the taxpayer. The taxpayer also has  the right to seek to quash to protect the taxpayer’s information from  being released to third-parties, though the IRS Reform and Restructuring  Act § 3415 amended this to protect disclosure to third-parties as part  of a collection attempt as distinguished from a taxpayer’s return  examination.
