So, what is metadata anyway? Under the IRS' Chief Counsel's definition, metadata is just about anything electronic. Specifically, it is "information that describes how, when and by whom a particular item or set of electronic information was collected, created, accessed, modified or formatted." The IRS' power to compel production of metadata is limited only by the vague guidance of I.R.C. Section 7602(a)(2), which allows production requests of virtually anything that "may be relevant . . . to a proper purpose for which the examination is being conducted, such as ascertaining the correctness of the return."
Coincidentally, the IRS' announcement comes almost simultaneously with the IRS' mandate that many taxpayers must file their returns electronically. Virtually every tax preparer must file returns electronically by tax year 2012. The Chief Counsel has made clear that the summons may be issued to third-parties. A taxpayer's accountant is specifically mentioned as one of these third-parties to whom the IRS may issue the summons.
The concerns here are apparent. Metadata is a trail of all the activities that went into preparation of tax documents, good or bad. Historically, the IRS' blasts into the age of electronic age have been lack-luster. Though, the possibility of IRS abuse here remains high. However, an argument can be made that certain electronic data is privileged from production if it is directly related to attorney advice on a legal issue. Your communications with your accountant and enrolled agent do not enjoy such privileges. Moral of the story: step back in a time machine to an era of exclusively paper records, or hire a local, licensed lawyer to provide you advice on your accounting issues.