NBC: 'Tonight Show' Days Numbered

Other unions could strike as well. Last week, Local 399, a Hollywood Teamsters union representing truck drivers, casting directors and location managers, told its members that while the union has a legal responsibility to abide by contracts with producers, individuals are protected by federal law if they decide to honor the WGA's picket lines.

"[Sympathy strikes] could definitely happen," said David Gregory, professor of labor law at New York's St. John's University. "When GM was dealing with a strike earlier this year, the Teamsters said they would honor the picket lines. There's definitely more of an immediate sense of militancy and a sense of workers saying we hang together."

Already, famous faces in front of the camera have voiced their support for writers behind the scenes. Jay Leno made an appearance at the Burbank studio where his show is taped to visit strikers walking a picket line. Julia Louis-Dreyfus, the "Seinfeld" alum and star of CBS' "The New Adventures of Old Christine," marched along with writers outside Warner Brothers' Burbank studios. And Tina Fey, creator and star of the NBC sitcom "30 Rock," picketed with WGA members outside NBC's Rockefeller Center studio in New York.

While those in the industry may stand up for the writers, Gray said it's unlikely the public will turn off their TVs in protest just because they see footage of picket lines on the news.

"Striking dramatizes the struggle ... [but] it's so indirect in that industry. It's not like picketing a food store. I mean, is anyone going to stop watching television? No, probably not," she said. "But public opinion will very often influence the parties. If it turns against the employers, that will put them under pressure, because they need to sell to the public."

The Associated Press contributed to this report.