Ten years ago the world was introduced to Twitter, a microblogging site offering users the chance to express themselves just 140 characters at a time. The social media platform quickly exploded to become a part of everyday life for an estimated 320 million active users. Not surprisingly, Twitter has also had a major impact on the law. Below, a hit list of Twitter's biggest moments in advertising law.

  1. #Copyright: Early on, Twitter intersected with copyright law. A 2010 lawsuit left the site in the middle when a photographer filed an infringement suit against Getty Images and Agence France-Presse, claiming the wire services made unauthorized use of photos he posted on Twitter of the devastating earthquake in Haiti. The dispute created law—with a federal district court declaring that Twitter's terms of service did not constitute a defense to copyright infringement—and yielded a $1.2 million jury verdict in favor of the photographer. The verdict highlighted the risk of appropriating material from social media sources such as Twitter, and reiterated that while content on such sites is arguably meant to be shared, it does not outweigh respect for content ownership.
  2. #Child-DirectedContent: As advertisers began to engage with consumers via Twitter, many added links from their sites and apps to their Twitter feeds. But one company ran into a problem when it linked from a child-directed website to the social media platform. Stuffed teddy bear retailer Build-A-Bear, Inc., featured a yellow blimp reading "Follow Us!" with hyperlinks to Twitter and other networking sites. In a self-regulatory proceeding, the Children's Advertising Review Unit recommended that the links be removed, and expressed concern that the links could be used before a visitor was appropriately age-gated. Build-A-Bear agreed to remove the links and advertisers learned an important lesson.
  3. #FTCTrendsetter: Against which social networking service did the Federal Trade Commission (FTC) bring its first case? That's right, Twitter. In March 2011 the agency charged the company with lapses in data security and the failure to protect users' personal information. These errors allegedly resulted in unauthorized access on two occasions, when an intruder was able to obtain an employee's administrative password and then reset user passwords and send unauthorized tweets. In one famous example, the intruder hacked then President-elect Barack Obama's Twitter account to tweet his followers about an offer to win $500 in free gasoline. To settle the charges, Twitter agreed to a 20-year prohibition on misleading consumers about its security and privacy, and to establish and maintain a comprehensive information security program.
  4. #Twibel: Almost single-handedly, Courtney Love created a new cause of action involving Twitter. Twibel, or libel on Twitter (also referred to as Twitter defamation), first appeared in 2010 when Love referred to a clothing designer as a "total scumbag, lying ripoff" and a prostitute in a Twitter rant. The designer responded with a defamation suit, which settled just prior to trial for $430,000. Love was again accused of Twibel in a second suit, this time by her former attorney after Love tweeted that she was "devastated" the lawyer was "bought off." That case made it all the way to trial, where a jury sided with Love. A California appellate panel affirmed the verdict earlier this year. The cases both serve as a reminder that despite its character limit, there is still room for potential liability on Twitter for defamation.
  5. #Hashtag: The term "hashtag" entered the popular lexicon thanks to Twitter, and the term has become so popular that it has increasingly appeared in trademark filings, as companies and brands seek to protect their intellectual property. According to a new study by Thomson Reuters' CompuMark, 1,390 applications for trademark-specific hashtags were filed globally last year, up from just 7 in 2010. The majority of hashtag applications can be found in the United States (1,042), followed by Brazil with 321 and France with 159.
  6. #Sponsorship: Could a hashtag cause a sponsorship deal to go sour? Actress Octavia Spencer answered in the affirmative in her lawsuit against Sensa Products seeking the remainder of payments under her $1.25 million agreement with the company. Spencer claimed she signed on to promote the weight-loss product and did so in compliance with the applicable FTC Guides Concerning the Use of Endorsements and Testimonials in Advertising. Her tweets included "Just had the best breakfast meatless sausage, banana pancakes, sensa! @Sensa Weightloss!!!!! #spon." In her complaint, Spencer described five occasions where Sensa executives allegedly requested that she remove the "#spon" from her tweets. She refused and Sensa eventually terminated the contract claiming poor sales. Spencer won a $940,000 default judgment against the company, but her suit highlighted the Catch-22 of complying with the Guides: while advertisers and their endorsers are required to designate paid tweets, consumers may be less apt to be engaged or interested in such communications.
  7. #PublicityRights: According to actress Katherine Heigl, a single tweet is worth $6 million. At least that is how much she requested in damages in her Lanham Act and right of privacy and publicity lawsuit in New York federal court against Duane Reade. The pharmacy chain tweeted: "Love a quick #DuaneReade run? Even @KatieHeigl can't resist shopping #NYC's favorite drugstore," which included an image of Heigl leaving a Duane Reade store carrying store-branded bags. When the retailer failed to remove the post at her request, Heigl sued over the "exploitation" of her "carefully and deliberately protected" professional name, likeness, and persona. The suit ultimately settled but provided a valuable reminder about respecting the privacy and publicity rights of celebrities in social media marketing.
  8. #Ownership: Who owns a Twitter account—the employee who operates the account or the company named in the handle? Noah Kravitz, a product reviewer and video blogger for website PhoneDog, signed up for a Twitter account with the handle "@PhoneDog_Noah." By the time he left the company, the account had more than 17,000 followers. Kravitz changed the handle and then began working for a competitor. PhoneDog sued, arguing that Kravitz misappropriated trade secrets because the Twitter followers were the equivalent of a stolen customer list. The parties ultimately reached a confidential settlement, but not before a federal district court denied Kravitz's motion to dismiss, ruling that PhoneDog had sufficiently alleged that its economic relationships suffered due to Kravitz's actions. The former employee's conduct resulted in diminished traffic to the PhoneDog website via the Twitter account, which in turn decreased the number of page views and discouraged advertisers from paying for ad inventory.
  9. #BrandVigilance: As the number of Twitter users grew exponentially, so did the number of Twitter imposters. Brands faced the proliferation of unauthorized Twitter feeds using the names and likenesses of well-known mascots such as the Pillsbury Doughboy and Tony the Tiger. And while General Mills tweeted about frozen vegetables from @GreenGiant, a marijuana dispensary (@420jollygreen) shared less wholesome social media messages. The lesson: Be vigilant and police Twitter activity that could tarnish a brand.
  10. #PRNightmare: Advertising in social media took on a different meaning after one flyer used a new approach to complain about a company's service. Hasan Syed purchased a promoted tweet in the New York City and United Kingdom markets to complain after British Airways lost his father's luggage, with messages such as "Don't fly @BritishAirways. Their customer service is horrendous." Syed's tweets—and the airline's less-than-stellar response, claiming it couldn't message him directly—were picked up by various news outlets which compounded British Airways' customer service problems. Every airline loses luggage, but the story reiterates that advertisers must keep their social media knowledge and skills sharp to avoid a high-profile brand embarrassment.