The San Jose-Milpitas district of the Santa Clara County Court issued the first search warrant for a computer system on 19 February 1971.
The warrant states that on 04 February 1971, the President of Information Systems Design in Oakland, CA, discovered a set of “key punch cards” connected to a computer terminal. The punch cards contained a program that provided a computer with remote plotting capability. This computer program was a trade secret valued at $15,000 ($106,000 in 2022 dollars; Becker, p 34).
Law enforcement seized tapes and a directory of all files held by a magnetic drum mass storage system built by Sperry Rand Corporation for UNIVAC called Fastrand (Becker, p 38).
According to the Computer History Museum, this event “ushered in a new era that would lead to increasingly sophisticated methods of encryption to hide computer files from law enforcement agents.”
Punch cards were made of stiff paper and contained holes punched by hand or machine; the holes represented computer data and instructions. The IBM card became the de facto standard.
See Operational Guide to White-Collar Law Enforcement. Becker, Jay. The National Center on White Collar Crime, Battelle Law and Justice Study Center. ND (pdf).