"Don't Commit Crime" is stated on one of Hertfordshire Constabulary's posters - "All fuel must be paid for" has been added on posters at petrol stations.
Language watchdogs the Plain English Campaign said the notices were funny, but an insult to people's intelligence.
Herts police defended the notices saying the obvious was worth stating if it had any impact on crime.
A police spokeswoman said: "We are not saying it is going to stop hardened criminals but it may make someone who is nervous think twice."
The campaign group described the signs as examples of "talking in a vacuum".
Friday, July 09, 2010
In a world where "Its OK as long as you don't get caught" has become the norm it is about time that we take the direct approach ... "DON'T COMMIT CRIME"
Further, 'me thinks they doth protest too much'. To complain that such a direct approach is "an insult to people's intelligence" only bolsters my belief that the critics live in some rarefied ivory tower well away from Bubba and his pick-up truck.