Michelene Meusa, Reneka Wheeler and their two children, who have been living on the streets for several months, moved into the house in the Pittsburgh neighborhood of southwestern Atlanta Thursday, The Atlanta Journal-Constitution reported.
The owners who lost the house to foreclosure have approved the move, Meusa said.
"We're taking one back from the bank," she added.
M&T Bank of New York, which holds the deed on the house, told the newspaper it is trying to find out what is going on. Police said only a complaint by the bank will trigger any action.
Tim Franzen, an Occupy spokesman, said the couple is involved in a "risky act of civil disobedience."
"We're doing what the banks have been doing to us for years," he said.