The public should be 'clued in' to what's happening. [=should be told about what's happening]
He doesn't have a 'clue' when it comes to fixing cars. [=he knows nothing about fixing cars]
He's totally 'clued in on' [=he knows a lot about] the latest computer developments.
(..) Dialogue: Marked=..,Default,NTP,!Effect,l see that you,\Nlike so many before you... Dialogue: Marked=..,Default,NTP,!Effect,l trust by now\Nyou realize what it does. Dialogue: Marked=..,Default,NTP,!Effect,Let me give you a clue. Dialogue: Marked=..,Default,NTP,!Effect,The happiest man on earth... (..)2001 Harry Potter and the Sorcerer's Stone