A humerous diagnosis of a reported problem with a computer, that, like
PEBCAK, while phrased in terms of keyboardhardware, actually blames the user.
A "nut" or "nutcase" is English slang for a mad person and "to let someone loose on something" means to give
them uncontrolled access, with the suggestion that they may not be ready. The expression is a play on the
word "nut", as in nut and bolt, which might be found in a keyboard and, if loose, might cause problems.