A federal lawsuit is starting following bitter antiwar protest arrests, and the plaintiffs say a rule against backpacks violated their constitutional rights.

The plaintiffs said there's no law against taking a backpack to a protest and said when the police tried to enforce such a rule they went too far.

Protesters picketed for days as the Army shipped military equipment for the fourth Stryker Brigade through the Port of Tacoma.

One key issue was a blanket rule prohibiting backpacks from designated protest zones.

A number of people were arrested for violating that rule, though a municipal court later dismissed those charges.

The plaintiffs said that policy was meant to discourage protesters from exercising their free speech rights.

They're also claiming that the City of Tacoma's overall response to the protest, including video recording and checks of license plate

numbers, were intended to discourage protesters from coming.

The lawsuit seeks damages and asks for a determination that the policy prohibiting backpacks in protest zones is unlawful.   

The trial, which starts Monday, is expected to last three weeks.