St. Louis Cardinals manager Tony La Russa sued Twitter in California in May after an imposter set up an account in his name on the social media network. Mr. La Russa withdrew the case a month later, but other celebrities and public figures, including Tina Fey, Christopher Walken, Condoleezza Rice and Bill Gates, have been victims of so-called “twitterjacking.”

Tracking the situation is Bill Coats, a partner in the Palo Alto, Calif., office of White & Case. Mr. Coats, the past chairman of the American Bar Association’s Section of Science and Technology Law and its computer law division, recently published an article about the intersection of social media sites like Twitter and right-of-publicity laws, which control the commercial use of one’s identity.