This review process means the IRS may need 4-6 weeks from this date to issue a refund.

FORBES: IRS, H&R Block Release Statements About Processing Delays

This means the IRS may need as much as 4-6 weeks from this date to issue a refund to the taxpayer.

FORBES: FAFSA, Tax Return Delays Could Slow College Enrollment Decisions

Whistleblowers may be eligible for a reward by filing Form 211, Application for Award for Original Information, and following the procedures outlined in Notice 2008-4, Claims Submitted to the IRS Whistleblower Office under Section 7623.

FORBES: This Year's Dirty Dozen Tax Scams

With new filters, the IRS discovered 4.1 million "problems" with Social Security numbers--an increase of more than 3 million from the year before.

CNN: An Overtaxed IRS

But one reason this misconduct occurred was that after Citizens United, the IRS was deluged with thousands of applications for 501(c)(4) tax-exempt status, and many of the organizations were obviously political groups claiming to be "social welfare" organizations.

CNN: The real risk of the IRS scandal

The IRS had little interest in 501(c)(4) political activities until the 2002 McCain-Feingold campaign-finance reform.

WSJ: David Rivkin and Lee Casey: The IRS and the Drive to Stop Free Speech

Specifically, the IRS was looking into whether donors to certain tax-exempt organizations organized under section 501(c)(4) of the Tax Code would be liable for gift tax on donations that were, in many cases, well into the six figures.

FORBES: IRS Drops Investigation Into Contributions (Tax World Drops Jaw)

The IRS review occurred after officials noticed that the number of applications for 501(c)(4) tax-exempt status doubled between 2010 and 2012.

WSJ: IRS Apologizes for Scrutiny of Conservative Groups

Tea-party groups complained often to lawmakers last year about excessive IRS scrutiny in processing their 501(c)(4) applications.

WSJ: IRS Apologizes for Scrutiny of Conservative Groups