BOSTON >> The Massachusetts attorney general has sued a Waltham law firm it alleges used unfair and deceptive practices to collect debts from hundreds of thousands of state residents.

Attorney General Maura Healey alleged in a complaint filed in Suffolk Superior Court that Lustig, Glaser & Wilson PC, has filed 100,000 lawsuits against Massachusetts residents and collected more than $110 million since 2011, preying on some of the state's poorest people, in one case taking out a civil arrest warrant against a 90-year-old woman.

Healey said the firm "used the judicial system to intimidate and harass people," and in many instances collected debts based on inaccurate or incomplete information.

A lawyer representing the firm tells The Boston Globe his clients cooperated with Healey's investigation and "look forward to being vindicated in court."

Information from: The Boston Globe,