However, if you recognize capital losses, there are likely to be undesirable nontax consequences.

FORBES: Don't Rush To Recognize Capital Gains Or Losses

That caused concern about the dissemination of taxpayer information for nontax purposes.

FORBES: IRS, Police Consider Sharing Info as Tax Fraud Increases

Mr. Paschall did not attempt to provide a nontax business, financial, or investment purpose for what he did, and this Court cannot ascertain one.

FORBES: No Time Limit on Excise Tax on Abusive Roth IRA

Mr. Young, who has won three big nontax whistleblower cases, wouldn't disclose his client's name or firm, but did say the person is retired.

WSJ: Taxes: How To Turn In Your Neighbor to the IRS

Some tax planning--for example, using a family limited partnership to reduce the taxable value of gifts--holds up best when it's done for nontax reasons, too.

FORBES: Protect Your Assets

Heartened by the success of a whistleblower program for nontax issues such as government contracts, Congress overhauled the special tax provisions on whistleblowers and set up the IRS's large-award program.

WSJ: Taxes: How To Turn In Your Neighbor to the IRS

Under the old law expatriates could apply to the Internal Revenue Service for a ruling confirming they had left the U.S. for nontax reasons and were therefore exempt from the ten-year levy.

FORBES: Congress makes another grab at expats' money.