And by 'random', this week we really do mean random. OK, so it's just a shitty bit of scawl on City Road, but is there anything more behind the message 'Brooke Shields Alphabet" that we're not getting? Is it some kind of advert for the V&A's surreal exhibition?
Your theories please.
UPDATE: All reported sightings are mapped here. Please add further examples to the comments and we'll map those too.