It's weird and surprising when you first see these as Michael's email to me shows while sending the photo to me from his iPhone:
"Looks like some sort of portable scanner, complete with 3 policemen and a setter-upper man, just in time for Friday rush hour!
Don't know if this is common at other stations or something to do with Boris, but thought you may be interested.
Personally, I think there may be more dangerous places to target than leafy Chiswick!"
There is growing public anxiety about fatal stabbings, shootings and teenage gangs, particularly in large cities like London and the scanners seem to be working.
My response was initially that I thought the police needed "quiet" areas to test this first. But I'm not so sure now. Violence can happen anywhere, even in suburban leafy Chiswick. I've not been through Turnham Green since this has been installed and I wonder how many people actually notice it. But again isn't that the whole point of them?