When the air traffic computers in Swanwick, Hampshire, take over from the current systems in 2001 or 2002, they will continue to use current the data processing system, Wright said.

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Wright was on the existing system after being convicted of theft in 2003, and when police found his DNA on the bodies of some of his victims they matched it with his profile.

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That was all written into the rulebook in the last parliament by the Wright Committee, which designed the new system of elected committee chairs, with the aim of preventing party political attacks on them.

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"A data problem caused the system to shut down, so the plans had to be manually produced, " Wright said.

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Eventually Wright found a specialist and was diagnosed with multiple sclerosis, a debilitating disease that involves the immune system attacking the central nervous system.

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Often, Wright would patch the most obvious vulnerabilities but leave esoteric ones unpatched, allowing hackers to exploit the system as he monitored their behavioral patterns.

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