NARRATION: Meet Bryan Denny

BRYAN DENNY (MILITARY VETERAN): My name is Bryan Denny. Im a retired U.S. Army Colonel.

NARRATION: In 2016, Denny, whos a decorated veteran, was living in Virginia with his wife and son when he received a strange message from a woman on the professional networking site LinkedIn.

BRYAN DENNY: She told me that she had been talking to me for several weeks. I was on a humanitarian mission in Syria and I was coming to Montreal to spend time with her. And, uh, I had to tell her that none of it was true.

NARRATION: It turned out shed been chatting online with a man who posed as Denny with Dennys own photos and scammed her into sending him money.

BRYAN DENNY: She said, you should go in to Facebook and search for your name.

NARRATION: The search revealed dozens of scam profiles.

BRYAN DENNY: The scammers really didnt try to hide the fact that they were using my name or my image, and they were all fake.

NARRATION: More women started reaching out to Denny, and he discovered that his photos were being used as part of a bizarre criminal racket throughout the internet.

BRYAN DENNY: Ive seen my profiles on Facebook, Ive seen em on Instagram, Twitter. Ive been on Christian Mingles. Bryan Denny, Scott Denny, Craig Denny, Ricky Sanchez.

NARRATION: The scammers lure victims into relationships, then ask for cash for fake medical bills or a plane ticket. They use photos of Denny in his Army uniform to target women from military families who are sympathetic.

BRYAN DENNY: In some cases their husband was a soldier, brother was a soldier, and they just want to do something nice for someone in uniform. By the time they realize this really just happened to me, and I gave away my, I gave away my kids inheritance, I have nothing left. And its emotionally embarrassing, its devastating, and its really hard to come back from.

NARRATION: And it isnt just Denny.

ARCHIVAL (CBS NEWS, 8-22-19):NEWS REPORT: Victims lost $143 million in romance schemes last year.

NARRATION: But Denny says people can find out if a profile picture or any image is genuine by searching if there is anywhere else that image exists online. Its called the reverse image search.

Here, Denny has come across one of his profile pictures on a scam Facebook account, and is going to do a reverse image search of it. He simply right-clicks on the image and saves it. Then, he opens

BRYAN DENNY: Drag that image to where it says drop image here. Its pretty simple.

NARRATION: Once hes done that, he gets a series of results that he can look through to find out more about the image. And by clicking on find image source, he finds links that make it clear the image is being used in scams.

Despite his efforts to stop the scams, Denny says the problem has only gotten worse.

BRYAN DENNY: I get five to six different messages through Messenger every day. Its someone whos been talking to a scammer and is now trying to sort things out.

NARRATION: He says that people can protect themselves with the reverse image search by right-clicking and saving the image, dragging it into Google image search, and scrolling through the results to find where else the image has shown up online. That way, you can use the internet to check the internet.

BRYAN DENNY: Youve got to know that youre stepping into a jungle, and youve got to step into that jungle armed with the tools to help you survive.