When advertisers launched a campaign last September for the pain reliever Motrin, they hoped to attract the attention of mothers whose backs might be sore from wearing baby-carriers. The advertisements implied that while baby-carriers might be fashionable, hauling a child around could be painful.

Mothers were not amused. Soon after the ads were released, anti-Motrin campaigns appeared on Facebook and blogs. Outraged mums, furious at the suggestion that their babies were a hassle, posted rebuttal videos on YouTube. Through Twitter, the microblogging service, thousands of people attacked the company.