Robocalls are on the rise and have become a regular annoyance for the millions of Americans who complain to regulators about them.

Why it matters: The telecom industry and policymakers have taken steps to curb the influx of calls, but efforts have so far haven't made much of a dent in the problem. Still, some hope recent changes will stem the tide of annoying — and sometimes costly — robocalls.

By the numbers:

The robocall problem is growing.

• There were roughly 4.1 billion robocalls in May, 2018, according to YouMail, which provides call-blocking software.
• It was only 2.6 billion nationwide a year prior.

Consumers are frustrated.

• The Federal Communications Commission receives around 200,000 complaints a year about unwanted calls, a spokesperson said.
• The Federal Trade Commission reports that in the 2017 fiscal year, there were about 4.5 million complaints about robocalls violating a telemarketing rule.

The financial consequences.

• A study by Truecaller, which makes caller ID software, estimates that in 2017 the total cost of phone scams was roughly $9.5 billion.
• 21 Chinese immigrants had, as of this spring, lost $2.5 million to a robocall scam aimed at Chinese speakers, the NYPD said in April.

The bigger picture

Robocalls are hard to combat because because of the complexity of the telephone networks — which involve many different phone companies — reports the New York Times. Scammers have also taken to "spoofing" telephone numbers, which is why consumers see automated calls coming from numbers with their area code.

• The national Do Not Call list failed to head off the recent wave of calls.

Yes, but: A renewed offense against the calls could reduce them over the next few years.

• Telecom carriers are planning to roll out a system for verifying legitimate calls soon, the Wall Street Journal reports. The FCC is moving towards creating a standard for authenticating calls.
• The FCC has also created rules that allow phone carriers to block malicious robocalls.

Editor's note: This story was updated to clarify that robocalls violate a broader telemarketing rule, whether or not the recipient is in the national Do Not Call registry.