The Insolvency Service is warning that it has closed down 78 companies in the last 3 years which were operating scams and specifically trying to target elderly people.
Some offered mobility equipment such as stair lifts, either not delivering the goods or overcharging. Others ripped off their victims over fine wines, fire alarms or worthless plots of land.
2,000 were affected, losing £28m. But it's quite obvious that this is just the tip of the iceberg. Trading standards officers around the country are dealing with more cases every day.
Older people and their families need to be on their guard, because in these tough times rogues may be even more tempted to try it on.
88 year-old May Bell was one of the victims, after a salesman came in to her home to flog her a stair lift.
She was left £1,800 out of pocket and trapped on the ground floor of her house, because the company didn't complete the installation.
Another victim described to me how the calls multiplied once he had had a brush with one of these con merchants.
He doesn't want to be named but he lost tens of thousands in a rip-off using gold coins.
Everything seemed to be going fine to start with - that's a hallmark of a lot of these operations. They string you along to gain trust.
After doing various successful deals, he sent off some valuable coins to be sold. Then - nothing. Until the police swooped on the perpetrators.
But new companies started to phone him with similar offers. Each one that gets shut down spawns several more masquerading under different names, as the fraudsters move on and spread out.
So once your loved one is a list, he or she will be contacted again by the same unsavoury characters, or by friends who have bought the list.
There is an even more sinister side.
Suspicious types will scour a neighbourhood, looking for tell tale signs which betray where an elderly or vulnerable person might live.
It might be that a mobility scooter has been left outside, or that there's a handrail on the porch. Or they just keep an eye out, watching who goes in and out and whether friends or family are around.
It's nasty, but it really happens. Some will leave marks on the wall to indicate whether the occupant has money and is easily conned. (Here are some more of the tricks they use.)
How can you deal with this? Don't accept sales calls by phone or at the door - say no. Do arrange to have someone you can call on for advice.
As for family and friends, it's our duty to check and keep checking and make sure that a vulnerable person knows how to contact us to ask for help and advice.
Here is some useful information from Age UK, Citizens Advice, and the Financial Services Authority.