This notice looks normal enough. But in fact, as it says, it is highly advanced.

It is made from a new kind of e-paper which can change instantaneously to display anything.

It can use Minority Report style retinal scans to identify anyone walking past.

It can launch microscopic nanites like dust – any which land on you will work their way into your bloodstream and constantly monitor you, sending health information to insurance companies and your location to the NSA, GCHQ, Mossad and the Russians.

It’s on a narrow canal towpath because anyone walking past will be forced to walk close to it.

Advanced indeed. And it looks so innocent.