“We want speculators out of our community,” she said in an interview on Monday. “They’re coming in, they’re profiting off harm that’s done in our community and we want them out.”

[Read about how rising rents are destabilizing California families. ]

Two months after entering the house, Moms 4 Housing had morphed into a Bay Area-wide phenomenon, rotating through newspapers, TV and social media that elevated the saga into a compelling moral drama that pit moms seeking housing against a company seeking profit. The movement hit its apex this week, after a judge ruled that Ms. Walker and the other families living there had to leave the home.

Aware that sheriff’s deputies could arrive any moment, a crowd of about 50 supporters had packed the street Monday afternoon, holding Moms 4 Housing banners and creating a human blockade on the home’s front steps. By evening the crowd had swelled to several hundred and shut down the block after the Moms 4 Housing text message chain alerted supporters that the police were said to be on the way.

This turned out to be premature, if barely. Early the next morning, sheriff’s deputies from the Alameda County Sheriff’s office arrived in riot gear with armored vehicles to remove them from the property, arresting two of the occupants and two supporters, according to news reports.