Last week I got contacted by Bob (he's asked that I don't share his full name for reasons which might become obvious).
Bob is 62 years old, retired, and recently relocated from Lancashire in the UK to live in Bedfordshire, to be closer to his children.
"On buying our house we obviously needed internet, and we selected TalkTalk to provide us with a phone line and broadband internet access," says Bob.
Last Tuesday, a router and phone were installed at Bob's home.
The following day, Bob contacted TalkTalk explaining that he had a problem connecting the router to his desktop computer. The issue was unable to be resolved during the support call.
The very next day (Thursday), Bob was rung up by people claiming to be from TalkTalk, offering to help him fix his tech support problem.
"It all seemed very plausible," Bob told me. "At their request, after some unsuccessful attempts to fix the issue, I gave them remote access to my iPad which was wirelessly connected to the TalkTalk line. Shortly afterwards, I became suspicious and ended the call. It then took almost 24 hours to confirm it was not TalkTalk as 'their systems were down'."
Bob has a very simple question: "How did the scammers know my brand new ex-directory phone number, which I had only just been given by TalkTalk, and hadn't shared with anyone? Furthermore, how did they know I had a technical issue with TalkTalk (unless every TalkTalk customer has one?)"
Bob says that TalkTalk haven't so far taken his concerns seriously, which is why he shared his story with me.
He rang TalkTalk's cancellations department, "but they didn't seem interested". He has also raised a formal complaint and awaits a response from the telecoms company which, of course, has something of a chequered history.
I don't know how scammers managed to get hold of Bob's brand new TalkTalk phone number quite so quickly. But if I was the person at TalkTalk responsible for investigating the customer complaint, one area of focus would be their call centres - where staff have access to users' personal information and might easily be persuaded to share it with criminal gangs.
Further reading: Security blogger Johnny Rage has an alternative idea on how scammers manage to get their hands on the phone numbers of TalkTalk customers.