Though automated calls have long plagued consumers, the volume has skyrocketed in recent years, reaching an estimated 3.4 billion in April, according to YouMail, which collects and analyzes calls through its robocall blocking service. That’s an increase of almost 900 million a month compared with a year ago.

Federal lawmakers have noticed the surge. Both the House and Senate held hearings on the issue within the last two weeks, and each chamber has either passed or introduced legislation aimed at curbing abuses. Federal regulators have also noticed, issuing new rules in November that give phone companies the authority to block certain robocalls.

Law enforcement authorities have noticed, too. Just the other week, the New York State attorney general, Eric T. Schneiderman, warned consumers about a scheme targeting people with Chinese last names, in which the caller purports to be from the Chinese Consulate and demands money. Since December, the New York Police Department said, 21 Chinese immigrants had lost a total of $2.5 million.