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3. Not the Child of an Orangutan

In February, Trump sued comedian Bill Maher who offered, on The Tonight Show, to give Trump $5 million if he could prove that his father was not an orangutan. (The comment was a spoof of Trump's offer to give $5 million to charity if President Obama would release his records and applications for colleges and passports.) Trump dutifully sent Maher a copy of his birth certificate, but the comedian never paid up. "He has not responded, and the reason he hasn't responded is his lawyers probably tell him, 'You've got yourself a problem,' " Trump told Atlantic author William Cohan. Maher later said, on his show, "Donald Trump must learn two things--what a joke is, and what a contract is."

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4. 'Predatory Lending Practices'

In 2008, Trump sued Deutsche Bank and Fortress Investment Group, along with a long list of smaller lenders who were financing his 92-story Chicago hotel and condominium project. Trump had personally guaranteed $40 million of Deutsche Bank's $640 million construction loan, but when the money came due in November 2008, Trump asked for an extension, citing the recession. His request was refused. In court documents, he condemned Deutsche Bank's "predatory lending practices" and partially blamed the global institution for causing the financial crisis, asking for $3 billion in damages. The bank countersued Trump for the $40 million he'd promised. The two sides finally reached an agreement, and in August 2010, the loan was extended for five years.



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5. 'Mob-Like Bullying'

Last month, Trump threatened to sue Angelo Carusone, the organizer of a campaign to get Macy's department store to drop Trump as a celebrity spokesperson and remove Trump-branded products from its shelves. The online petition claimed, among other things, that Trump had "long engaged in sexist behavior" and "used his public platform to deny the reality of climate change." In a December 27 letter, Trump's counsel accused Carusone of using "mob-like bullying and coercion" and informed him that if he failed to cease and desist, Trump would sue him for no less than $25 million in damages. Toward the end of February, Trump appeared to back off. "Looks like a lawsuit against GoAngelo won't work," he tweeted, "--my ties and shirts doing too well at Macy's--he's actually helping. I have no damages!" But when asked about the lawsuit more recently, Trump's lawyer told U.S. News he'd have to "see how these things play themselves out."

6. A Big Boy Lesson

In 2011, the song "Donald Trump" by rapper Mac Miller turned into a viral YouTube hit. In between obscene lyrics, the rapper vowed to "take over the world when I'm on my Donald Trump shit." Trump was not amused when Miller sent him a wooden plaque in honor of the song's success. "I'm now going to teach you a big boy lesson about lawsuits and finance," Trump threatened over Twitter. "You ungrateful dog!" Miller tweeted back, "i'm not trying to put any negative energy into the world. @realDonaldTrump let's be friends." So far, no suit has been filed.