Readers also shared their tactics for dealing with the calls.

“Sometimes I give the scammer a made up credit card number one digit short of the full complement, then keep changing the sequence when they read it back,” Bruce in Cleveland wrote. “I can still make dinner while I’m doing this on speaker phone.”

Here is a selection of the responses. They have been edited and condensed.

Personal Experiences With Fraud

“I thought I was impervious to scams since I had installed security software from a known, trusted company (‘ABC’). “Two months ago ABC sent me an email saying that I didn’t have adequate protection on my system. The email asked me to download a new module to update my security package. Not even thinking remotely about potential problems with this approach, I did as they asked. But the module wouldn’t install, and it gave me an error code and a number to call. Not only that, but I was called several times from someone claiming to be their representative who would help me with this problem. So I called them back and was connected to ‘Chris Coleman,’ a fellow with a deep accent who spoke broken English. ‘Chris’ told me he needed to ‘take control’ of my system to search for viruses. Long story short, I finally tumbled to the truth when Chris asked me for my credit card to ‘buy’ some new, improved security software!”

— Thomas E. Heines in Dallas, who has worked in information technology

“My 82-year-old mother, whose memory and judgment are fading, has been getting calls from ‘Windows tech support’ for a couple years. I keep telling her to just hang up, it’s a scam, but she keeps talking to them. So far they only got $300, but last month there were a couple close calls. One guy took control of her computer and tried to have her sign up for online banking (she called me before they got any money). I am taking steps to limit her access to her money. This is the only way to protect someone like her from these awful scams.”

— Eric Beldoch in Ardsley, N.Y.

“Ashamed, for what the youth of my country has got themselves into. I hope such scammers are busted as early as possible. It’s not just American citizens; international students are also targeted. My cousin was duped of 3,000 Australian dollars and another one of $4,000.”

— Aryan Nair via Facebook

“My 90-year-old father was tormented by these people for a year. He believed they were going to fix his computer, and he gave them his log in and password. And he paid them for lifetime service on his PC. “Then they started calling and threatening him to send more money. Said they would destroy his PC. I had Montgomery County police (in Maryland) come to the house and provided them the contact info. They said they see this all the time and there was ‘nothing they could do.’ “I told them I had contacted the F.T.C. but there was no one to speak with — only a ‘contact us’ form — as if that would help. “I begged Dad to stop answering the phone, but he didn’t because he’s lonely and that’s what his generation does when the phone rings. “Returned after a three-day trip to find receipts on the table for $300 worth of iTunes cards. Dad doesn’t even know what iTunes is. “So a feeling of total helplessness. No legal authority in this country is able to protect our elderly from this kind of fraud.”

— Mel Craig in Washington

“Being the victim of financial fraud is often one of the first signs that someone is suffering from this disease [dementia]. Caller ID is of no use to someone who is beginning to lose their faculties. “I watched my father deal with this on a daily basis for six years, screening phone calls, intercepting letters from fraudulent charities and contests (an average of about six per day), and doing other things to protect a relative with dementia. “One called back and told him to look out his front window; he was about to be killed by someone waiting outside.”

— Richard Garner in Germantown Hills, Ill.

‘Promoted if We Got Tough’

“As a young man I was trained as a collections agent by a major retailer. I was taught all manner of tactics to get people to pay their bills. We were paid a bonus and promoted if we got tough. There was no Fair Debt Collections Practices Act then, but still there were laws and our employer taught us to ignore them. I helped set up call centers in Madras, Bangalore and Bombay, so far back those places still had those old names. “Over the years I’ve also interviewed for jobs in the U.S. that involve scamming people over the phone. Never took the job, though. This kind of fraud doesn’t just originate overseas. We need a stronger Consumer Financial Protection Bureau, yet the president-elect wants to gut the office.”

— Thomas H. Williams in Annapolis, Md.

Sharing Defense Strategies

“I do not ever, ever, ever answer a call from a number I don’t recognize — ever, not at home, not on my cell, not at work. If it’s important, and genuine, the caller usually leaves a message, and I return the call if I choose.”

— AMM in New York

“One time, with one of these I.R.S. Treasury calls, I was particularly incensed, knowing that these scammers were going to victimize more gullible people. So I called them back, and lectured the guy who answered. He hung up. So I called back again — and lucky me, the same guy answered the phone. Again, another lecture, and I worked to shame him as much as I could. He hung up. “Yeah, I called again — and, again, the same guy. This time I pointed out to him the sad futility of his life, pointing out how he clearly had some basic skills — good enunciation, good tone of voice — and how he could be working a legitimate job if he wanted to, yet he was pursuing life as a scam artist. He broke down crying, saying he had to pay his bills. But he got no sympathy from me.”

— Evelyn in Orlando

“I was able to get the Microsoft scammers to stop by saying in a stern voice ‘O.K., Detective — you’re on the line? This is the fraudulent call I want you to trace,’ and pressing any button on the keypad, which emits a tone that sounds like the start of a recording. “I am convinced they target older people, thinking we are too stupid to realize these are phony calls.”

— Ellen D. Murphy in Portland, Me.

“I get the ‘Microsoft Support’ calls fairly regularly. The usual pitch, ‘We have detected that your PC is infected …’ My response is to play along: ‘Oh, no! No, I am not in front of my PC right now …,’ ‘I’m going to put the phone down while my PC boots up …’ “Then I just put the phone down. I wait until I hear the scammer shouting themselves hoarse for me to come back to the phone. “Then I ask them if their mother knows that they are working as a scammer. That’s when they curse and hang up.”

— Jeff in the Slope in New York

“The approach I use when receiving such scamming phone calls is to say: Please give me your phone number and location, and I will have my attorney call you.”

— MNW in Connecticut

“It happens in Canada, too. I was getting dozens of calls a day — really annoying as I work from home a lot. I let them go to voice mail except for once where I told the guy where to go. OMG! He really got mad. We’re urged to report such incidents to the police. However, nothing stops it.”

— Joan Morrissey via Facebook

“Got a call from an Andrew McGowen, supposedly an F.B.I. agent informing me that my I.R.S. tax issues will cause me to be arrested in the next 24 hours if I did not send a gift card loaded with $2,500 immediately. His heavily accented English didn’t seem right for someone of Irish heritage. “Having a little fun, I wasted as much of his time as I could, ending with a question: ‘How is the weather in Mumbai today?’ Silence.”

— Ken in Mont Vernon, N.H.

Sullying India’s Reputation

“Every week I get two or three early-morning scam calls from India, and I am sick of them. I get either the I.R.S. scam or the Microsoft computer virus scam. They have given me very negative feelings toward India.”

— Mary Ann Hymel in Bellevue, Wash.

“When I hear an Indian voice on the phone, I immediately distrust whoever it is. That is sad. These people are doing no service for their own country. They are giving India a bad reputation.”

— Elizabeth in Washington

Reflections on the Fraud

“What struck me most in this article is the statement that he made about Americans fearing their government. That was profound to me. And it speaks to the very reason why people fall for these scams. We shouldn’t fear being taxed to the point that when you receive calls like this, you immediately think of everything you will lose.”

— Crystal Means via Facebook

“I was the lucky recipient of probably 100 of these calls over several years, and I watched the scam evolve, with interest. At first, it was laughable: Guys with heavy accents, claiming to be ‘Steve Martin’ (seriously?), using language that was very British-influenced and awkward-sounding. After about three years, the caller became an educated sounding Indian woman, with the language and agency names considerably cleaned up. Then, the messages became computer generated so no accents and no names. “I think we’re unlikely to get smarter, but they can only get better at scamming.”

— Mosselyn in Silicon Valley