Brooklyn District Attorney Eric Gonzalez is warning New Yorkers to be on the lookout for one of the latest scamming trends: cryptocurrency scams, also known as "pig butchering."

“It comes from these scammers who liken it to the practice of fattening hogs before slaughter," Gonzalez said during a press conference at his office Thursday. "It's a metaphor for a process by which victims are lured into making investments and, in most cases, they don't realize that these investments are bogus until it's way too late.”

Scammers use different techniques, including dating apps. During the press conference, the DA's office showed recorded testimony of several victims, including an anonymous woman who said she fell prey to a crypto scam through the dating app Bumble, and ultimately lost about $118,000.

"He was trying to tell me about crypto because I told him I was in the process of a divorce and I’m trying to get my house. You know, I wanted to buy out my husband so I could just have the house to myself," she said.

Scammers also use group chat apps such as we chat, WhatsApp or Telegram to add victims to what appear to be legitimate chats about crypto investments. One man said this happened to him on Facebook.

"The actual amount that I saw that I traced all the electronic transfers, the wire transfers from my Chase account into the Coinbase, nearly $420,000," he said.

"Now what happens is at some point when a person tries to withdraw a large sum of money from this alleged profit that they've made that's when red flags really go up," Gonzalez said. "There's different techniques to stall that out. They'll tell them in order to withdraw this money, you've earned a tremendous increase in your initial investment and now you owe taxes."

To combat the problem, the Brooklyn DA is focused on disruption and prevention. On the disruption front, the office said it has seized over 20 web domains that have taken part in these scams, including a website called Coinformat, which has an accompanying app. Both can appear to be legitimate to the untrained eye. The Brooklyn DA's Office said scamming victims lost nearly $3 million from this website and associated domains.

Law enforcement officials said it is also hard to recover stolen funds.

"These funds are moving rapidly through a series of cryptocurrency addresses," said Brooklyn District Attorney Chief Alona Katz, who leads the DA's Virtual Currency Unit.

"They're being swapped into different types of tokens. They may go to exchanges that are not compliant with U.S. law enforcement," she said.

The office also said it’s hard to track down the criminals involved in the scams, which are usually organized crime rings or crypto crime syndicates. Some even involve scammers who are themselves victims of labor and human trafficking.

The Brooklyn DA is hoping making this information public helps prevent more of these crimes. The office is urging anyone who has been a victim to notify authorities immediately.

Last year, the NYPD reported 50 cases, but officials believe that's an undercount, as shame usually deters most victims of crypto scams from reporting the crimes to law enforcement officials.

The FBI estimates that last year over $3 billion have been stolen from U.S. residents due to crypto scams.