It's an unconventional way to snare criminals.
An account manned by Greater Manchester Police invited followers:
'Do you live in Little Hulton or Walkden? Hate the Police? Want to brag & rub our noses in it? RT if you have drugs & haven’t been caught'
Judging by the number of RTs so far (934 at the last count), there are quite a few police-hating drug-takers in Little Hulton and Walkden.
Inspector Steve Bailey of Greater Manchester Police told The Mirror: "The Tweet was issued in a humorous way to highlight the important problem of drug use and drug dealing. It received broadly positive feedback and has led to an increase in followers to the account."