know too much

know too much

cliché To know too much detailed or intimate information (about someone or something). The phrase implies that the person with such knowledge must be or will be prevented from divulging it to others, perhaps by nefarious means. If he's worked here for that long, he knows too much. Get him to sign an NDA. The accountant knows too much about our... less legal sources of income. Eliminate him.
See also: know, much
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

know too much

be in possession of too much important information to be allowed to live or continue as normal.
See also: know, much
Farlex Partner Idioms Dictionary © Farlex 2017
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References in periodicals archive ?
Especially in the South, where people didn't know too much at that time and weren't allowed to learn very much.