The arrest of a gang accused of being behind a major 'pension liberation' SMS spam campaign coincided with a significant drop in the volume of texts being sent in the UK, messaging security firm Cloudmark has reported.
Comparing the 30 days before the arrests by British police on 9 May to the equivalent period after that day, the firm found that this form of SMS spam had dropped by 78 percent.
Cloudmark's figures show that the campaign had ignited in October 2012, reaching peaks in November, February and April before the sudden and marked drop-off to much lower volumes since then.
Pension liberation spam is one of several common types of SMS spam that bombard UK mobile users despite the best efforts of networks to filter them out. Other well-worn types include PPI protection claims, payday loans and debt consolidation.
The pension 'liberation' the scammers push offers savers an apparent way to transfer investments to bogus offshore funds or release some of the capital in return for sky-high management fees.
"Hold a pension? Frozen or under performing? Receive 16% of the value in cash in just 6 weeks and into scheme returning 14% reply 'CASH' for info or stop to opt out," read a typical example of the messages sent to million of UK mobile phone users.
The UK's National Fraud Intelligence Bureau said at the time of the May arrests that thousands of UK pension holders were believed to have signed up to the scams without anticipating the serious consequences.
Nevertheless, "the problem has not been completely solved," suggested Cloudmark's Andrew Conway. "The life insurance company Phoenix reports that they have actually seen a significant increase in potentially fraudulent pension fund transfer requests since the arrests," he said.
This might suggest that the arrests had removed some of the individuals connected to its UK operation without disrupting those running it, who could be offshore. Pension scams are also promoted by cold calling.
In April, Cloudmark reported that a large fine handed down by the UK Information Commissioner (ICO) to a firm accused of being behind a surge in payment protection insurance (PPI) SMS spam had led to a marked fall in message volume.