I'm pretty the term originated with BBS's (Bulletin Board Systems) which were patterned after a literal bulletin board. Back in the day we used bulletin boards

I'm pretty the term originated with BBS's (Bulletin Board Systems) which were patterned after a literal bulletin board. Back in the day we used bulletin boards for posting public messages. Seriously, before the internet we used to just stick pieces of paper to a cork board with a thumbtack that was displayed in public places. From Wikipedia: "The first public dial-up BBS was developed by Ward Christensen and Randy Suess. According to an early interview, when Chicago was snowed under during the Great Blizzard of 1978, the two began preliminary work on the Computerized Bulletin Board System, or CBBS. The system came into existence largely through a fortuitous combination of Christensen having a spare S-100 bus computer and an early Hayes internal modem, and Suess's insistence that the machine be placed at his house in Chicago where it would be a local phone call to millions of users. Christensen patterned the system after the cork board his local computer club used to post information like "need a ride"."