One of the most insidious scams out there involves criminals impersonating IRS officials and threatening people with arrests or lawsuits for fictitious tax debt.

Fighting this type of fraud is like playing Whac-A-Mole. Just as authorities hammer down one con scheme, a new one pops up.

When the Treasury Inspector General for Tax Administration (TIGTA) began tracking such scams in 2013, the office was getting 9,000 to 12,000 calls a week. Now that number is 25,000 to 30,000, according to Timothy Camus, TIGTA’s deputy inspector general for investigations.

It used to be that the charlatans manually dialed for victims. Now they have advanced auto-dial technology that allows them to speed through hundreds of telephone numbers. And they manipulate caller ID to make it appear as if they are calling from the IRS.

TIGTA has been studying how many calls the con artists have to make before they trick someone into sending money. At the beginning of the year, it took 400 calls before they got a victim, but now it takes only about 215 calls, Camus told me. The scammers can snare 115 to 125 victims a week.

In a recent week, out of 120 people who reported paying scammers, 100 did so using iTunes gift cards. But the IRS won’t call you demanding payment, and the agency would never ask you to pay your tax debt using a gift card.

“We got a dreadful call from scammers with all kinds of demands and threats,” a reader, Gloria, wrote after my recent column about getting one of these calls. “It was a scary half an hour that they held us on the phone until we realized it was a fraud.”

Some concerned citizens try to take on the scammers in an effort to protect other potential victims. These people, fully aware they are targets of a fraud scheme, tie up the con artists on the telephone, hoping to engage them long enough to reduce — even by one — the number of additional people they can call. It’s a laudable mission but also dangerous.

“Rather than hang up, I keep leading the caller on for as long as I can,” wrote a reader from Massachusetts. “My goal is just to waste their time and frustrate them. My record is about 20 minutes before they caught on. I figure the more I can cost them the better.”

Richard, a certified public accountant from California, said he fights back because he’s tired of hearing from many of his elderly clients who are panicked when they get these calls. He decided to play along when he was dialed up by an IRS impersonator.

“When I balked at going to Wal-Mart and getting a debit card to pay them, [the scammer] got a little nasty, so I decided to teach him a lesson,” he said. “I have a really high-quality referee whistle. I gave him the biggest blast of the whistle that I could muster up and then hung up. Hopefully I busted his eardrum.”

Steve from California, sitting one day in his lounge chair with a cup of coffee, also toyed with a scammer. In his case, it was someone claiming to be from a major tech company offering to fix his computer. He quickly realized it was a ruse and told the man he was having trouble booting up his computer. That subterfuge endured for 20 minutes. He then wasted 10 minutes more pretending to look for a password. The total time before the scammer threw in the towel: 1 hour and 10 minutes.

Some readers wondered what the harm is in messing with the scammers as retaliation.

“I am well aware of these scams and will not respond,” one person wrote. “I am curious as to why I shouldn’t engage them. Is there a risk?”

Yes, there is. The best way to frustrate them is to hang up immediately. I know many of you are shrewd enough to suspect a scam. But some folks, the longer they listen, may be persuaded to part with some money.

Camus said there have been at least three reported cases in which scammers got mad and made prank calls to local law enforcement officials claiming there was an armed dispute happening at the person’s home. This strategy of payback has a name: “SWATting” because a SWAT team is sent to investigate the call.

If the scammers get your personal information, they could also target you through identity theft, Camus said.

“If they get angry, who knows what else they could do behind the scenes?” he said. “They are clearly criminals, and they have the time.”

It is tempting to toy with these scoundrels. But don’t put yourself at risk. Please, just hang up.

Write Singletary at The Washington Post, 1301 K St. NW, Washington, D.C. 20071 or singletarym@washpost.com. Comments may be used in a future column, with the writer’s name, unless otherwise requested. To read more, go to http://wapo.st/michelle-singletary.