Bugs and “bugs”
- accidental, even natural (bugs)
- intentional, even malicious (“bugs”)
Notebook entry reads: "Relay #70 Panel F (moth in relay): First actual case of bug being found". It's pretty transparent that Admiral Hopper intended her note as a joke. According to The Hacker's Dictionary, "bug" was in use for this type of thing in the 19th century, and even in Shakespeare. Also according to the Hacker's Dictionary, Hopper knew this (as if that wasn't clear from the note).
Full quote about Admiral Grace Hopper's invention of the word "bug", from MacTutor History of Mathematics Archive, which has a page full of endorsements on its site, including from the Encyclopedia Britannica, Magellan (search engine), etc.:
“From 1944 she worked with Aiken on the Harvard Mark I computer. It was while working on this project that she coined the term 'bug' for a computer fault. The original 'bug' was a moth which caused a hardware fault in the Mark I.”
Grace Hopper’s bug may have come from nature, in some sense of that word, but almost all other bugs have been introduced by programmers, either accidentally or on purpose.