Refers to a horny police officer's using a "
frisk" ('
cuz he's feeling "frisky") as a
selfish/shameless opportunity to "sample the merchandise" on an attractive fellow human.
If you're an extra-cute lady and you're not doing anything wrong while you're out driving, don't worry too much if you get puled over --- most likely the officer just wants to
cop a feel. Same deal with a "frisk" or a "pat-down", as
well... the
lust-crazed "dirty old man with a badge" is feeling "frisky", and so he wants to "pat" you "down there".