The Met's plan to counter terrorism by putting up posters in internet cafes has been put into action, with broad warnings against "inappropriate" web and email use.

Two notices labelled "internet code of conduct" and "internet policy" have been spotted by patrons in London cafes.

"Do not access, upload, download or view any inappropriate material that causes or is likely to cause offence to any members of the public, including images of literature of a sexual, violent or extremist nature," the Met cautions.

One of the posters warns that police will also frown on inappropriate or offensive emails.

Cooperating cafe owners will immediately terminate the user's internet session and report them to police, the Met adds in both posters. Downloading "certain" - coyly unspecified - material could constitute a criminal offence.

The posters, announced in March, are part of the "Prevent" strand of the Home Office's counter-terrorism strategy, CONTEST. Prevent has been widely criticised for alienating Islamic communities from police, rather than fostering the trust necessary for proper intelligence-gathering.

The Third Estate blog has picture of the Met's new posters here. ®