In 1962 Food Center Wholesale Grocers Inc installed a new IBM 305 RAMAC. That's when things started to go wrong. The faulty machine seemed to have a mind of it's own, and would spread chaos to grocery stores all around Boston.
Selected Sources:
https://archive.org/details/computerinsecuri0000norm - Computer Insecurity
https://bitsavers.computerhistory.org/magazines/Computers_And_Automation/196805.pdf - Computers and Automation article
https://archive.org/embed/sim_computerworld_january-01-08-1969_3_1 - Computerworld
