"Most cases start the old-fashioned way," said Ian Comisky, a partner at law firm Blank Rome LLP who represents taxpayers whose returns were flagged by the IRS. "You blab about it to a friend, colleague, spouse or girlfriend, and one of them turns you in."
Even your closest pals may be tempted to tattle, since the IRS offers whistleblowers a reward of up to 30% of any additional tax or penalties it collects from tax cheaters.
And with the popularity of social media, it's now much easier to publish private information publicly. So if you did something you think was questionable, don't post it all over Facebook.
From pet pigs to Playboy magazines, here are some of the most outlandish deductions taxpayers have tried to slip past the IRS.
|The weekend America's newspapers called Donald Trump a liar|
|Charles Osgood announces Jane Pauley as his successor|
|The life and crimes of Sin City's million-dollar mail fraudster|
|Exposed: The secret powerhouse processing millions in global fraud|
|How Lester Holt is getting ready for Monday's debate|