At the heart of this Islington estate, it is subject to regular vandalism by the local youth. The number (subject number is for the payphone to the left) rings loud but it's to call during school holidays. You can play tricks on them with the other number too: +442077001629. Will try to get a picture of the kids hanging around this one and will post it here with the one.
Also this is very close to where a local murder was carried out (off to the left of this payphone). You can read an article on it here.