A couple of months ago, your correspondent was writing an article for this website when the phone rang.
It was an unremarkable-looking mobile number, whose last three digits were 327. Upon answering, there was a slight pause before the line went dead.
The next day, a very similar number rang – identical apart from the last three digits being 485. Again, the line went dead.
Within the next week, the same thing happened with numbers ending in 663, 837 and 971.
Then the calls stopped. Until a month later, when a different batch of numbers began making similar calls – this time reporting an imminent disconnection of broadband.
The same pattern followed – one-time calls from numbers with only the last three digits varying, as criminals sequentially worked through a list of available numbers.
Making a nuisance of themselves
Nuisance calls are something we all experience periodically, but they’re increasing in prevalence at the moment.
In recent months, the Information Commissioner’s Office and Ofcom have both reported a surge in nuisance calls compared to the same periods in late 2019 and early 2020.
The reasons for this aren’t entirely clear, but may involve a greater ability to reach people during the day thanks to office closures, home working and furloughing.
(It could additionally be the case that traditional opportunities for scams have fallen as we travel less, use our debit cards less, generate less paperwork and generally spend less money).
It’s also interesting to note the phenomenon of calls coming from numeric batches of UK mobile numbers which don’t accept incoming calls.
If you ring back and the number is still in service, you’ll probably be greeted with an ear-splitting screech or simply silence.
However, ringing a number that’s just unsuccessfully called you isn’t advisable, because of the Wangiri fraud which has grown in prominence in recent years.
Here, a victim’s phone briefly rings from an international number, with no message being left.
Calling back may immediately use up any remaining credit on a pay-as-you-go contract, or incur punitive charges for every second you remain connected.
The number being displayed may not be genuine, since cloaking technology enables telemarketing companies to pretend they’re calling from somewhere they’re not.
This can even involve spoofing genuine domestic numbers, rather like the phenomenon of cloning legitimate vehicle registration plates for fraudulent purposes.
The recent surge in nuisance calls represents the latest stage in an ongoing cat-and-mouse game between scammers and industry regulators here in the UK.
The latter are hobbled by the fact most of these scams originate overseas, where British legislators can’t reach and industry bodies like Ofcom can’t take action.
The numbers themselves tend to be sold in batches, with personal and business numbers indiscriminately made available to all and sundry.
In some cases, personal details have been fraudulently obtained from ISP call centres, or acquired as part of high-profile data leaks.
However, efforts are being made to stem the tide.
Mobile network operators now make it easy to block and report fraudulent numbers, while services like Sky’s Talk Shield automatically block bots by forcing callers to verbally identify themselves.
Ofcom and the ICO are responding to the surge in nuisance calls by raising awareness, while aggressively targeting the people or companies responsible.
Even so, this issue will be impossible to fully solve without far tighter domestic regulation of cold-calling companies, and stricter international rules on data reselling.