Security services targeted input components - including keyboard and trackpad controller chips, and inverting converter chips - when police raided The Guardian newspaper over the Edward Snowden leaks last year.
The raid happened shortly after the newspaper started printing stories drawn from the cache of files that National Security Agency (NSA) whistleblower Snowden downloaded from NSA computers.
The government had demanded that The Guardian destroy the documents, which it did. But that was not enough for the security services, and police were sent in to seize computing equipment.
"Surprisingly, however, GCHQ were not just interested in hard drives nor did they destroy whole devices," claims Privacy International, which has led an examination of the hardware that the security services targeted.
It continued: "During our investigation, we were surprised to learn that a few very specific components on devices, such as the keyboard, trackpad and monitor, were targeted along with apparently trivial chips on the main boards of laptops and desktops."
Indeed, when the devices were returned to The Guardian, these chips had clearly been ripped out.
Coming at the same time that it was revealed that US security services have tampered with exports of networking equipment in order to plant bugs, the particular seizures of these devices indicates that they may have played a role in UK security services' eavesdropping.
Privacy International has now filed questions with the manufacturers of the devices to find out what information can be stored on those devices, retained and for how long.
"By getting answers to these questions, we can get a glimpse into GCHQ's understanding of IT security threats, but also give individuals the information to better understand the devices they use everyday and how they can protect their personal information.
"For instance, people and organisations may need to re-evaluate how they dispose of their computing devices, given the very specific hardware components destroyed by GCHQ," claimed Privacy International.
The devices in question were made by Apple, Dell, HP, Logitech and Microsoft.
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