Just as the writer of Doctor Who was signing copies of a new book for fans in a nearby bookshop, the message "Bad Wolf," a reference to the latest Doctor Who series mysteriously appeared on the Stefhan Caddick's electronic storyboard sign outside.

Next a local Big Issue seller was given a helping hand with a message that read, "Big Issue for sale here. Please buy one." But it was a mock-ominous message to the city as a whole that had most Saturday morning shoppers amused. It read, simply: "Good Morning Cardiff. Big Brother is watching. Look behind you."