Simon Crubellier's MI5 raises a few questions.
Was this the work of a disgruntled Spooks viewer? If that whitewash was peeled back would we find a similar Down With the Home Section of the Secret Service Bureau message underneath circa 1909? Could MI5 themselves be responsible thereby creating a climate of anti graffiti fear in which their own free-painting powers could be extended?
We'd ask more, but fear our lunchtime pasty from Greggs could end up smeared with polonium-210.