A primary school caretaker was found with "a bomb factory" in his bedroom and three letter bombs ready to send when he was arrested, a court has heard.
Police were led to Miles Cooper's Cambridge home by "a series of idiosyncrasies" in the manufacture of seven devices sent to forensic science laboratories and offices throughout the UK in the first months of this year, a jury at Oxford Crown Court heard.
When they swooped at 3am they found Cooper's bedroom was "basically a bomb factory" with three further devices "assembled, packaged and more or less ready to go".
Cooper, 27, from Cherry Hinton, Cambridge, denies eight counts of causing harm to people with explosives, two counts of using explosives to cause harm, one count of making an explosive, and one count of possessing an explosive.
Defence barrister Michael Wolkind QC told the jury that Cooper does not deny sending the devices but said he was not responsible for the injuries caused. He sent them because "of an overbearing and over-intrusive surveillance society".
But prosecutor John Price said the series of letter bombs caused "widespread public alarm and sparked a large-scale police investigation".
The first was opened by a receptionist at an Oxfordshire forensic science laboratory, Orchid Cellmark, on the morning of January 18.
On the same day LGC Forensics in Abingdon, Oxfordshire, and the Forensic Science Service in Birmingham received similar devices.
A fourth device was addressed to Alpha Security at the home address of the company boss in Kent.
A fifth was received at computer company Capita's London office days later on February 5, and a sixth arrived at Vantis, which is concerned with the administration of speed cameras, on February 6, said Mr Price. The final device arrived at the DVLA in Swansea later that week.
