Internet café owners are being asked to snoop on the online activities of its customers in a bid to combat terrorism in the UK.
According to the Met Police, several convicted terrorists used internet cafes to plot their attacks.
As a result, the police implemented a scheme in Tower Hamlets that asked owners of public Wi-Fi hotspots to check the online activities of customers.
Any suspicious online activity was then reported to the Met for further investigation.
The scheme, which is part of a £140m campaign to stamp out terrorism, is now being rolled-out in Camden, Harrow and Westminster. However, participation is voluntary and internet cafes can refuse to take part.
Establishments that take part are also issued with posters that warn consumers about the type of online activity that is deemed unacceptable.
"If the owner [of a public Wi-Fi connection] sees people looking at violent extremism they need to know who they can turn to," PC Jason Beynsberger told the BBC.
"Obviously every situation is different. We need to establish if there is something we need to investigate further, for example, if there's a pattern forming."
However, Arun Kundnani, author of 'Spooked: How Not to Prevent Violent Extremism', believes the move is "another step in the direction of creating a society of total surveillance".
"What is dangerous about this initiative is that it does not just focus on preventing access to illegal material but also material that is defined as 'extremist' without offering an objective definition of what that is," he said.
"It thus potentially criminalises people for accessing material that is legal but which expresses religious and political opinions that police officers find unacceptable."