(CNN) Hollywood's biggest labor battle in a decade is officially underway. The issue, as is usually the case, is money.

The Writers Guild of America is taking action against the industry's biggest talent agencies. A bevy of writers who are members of the guild have broken off ties with the agents who usually represent them.

The guild has 15,000 members, so the action could have sweeping consequences. This mass firing of agents has never happened before, so no one quite knows what's going to happen or how long it's going to last.

The two sides had been holding contentious negotiations until Friday, when the writers had set a deadline for talent agencies to accept its new "code of conduct."

A few hours before the deadline, the guild told its members that talks had failed, so it was time to cut ties with the agents.

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