In the lead up to the Cricket World Cup and Australia’s opening match against England at the MCG on Saturday, mysterious rock posters began appearing around Melbourne asking anyone who had seen a missing pair of balls (of the cricket variety, of course) to please return them to the English cricket team. Later in the week, a billboard on Punt Road revealed the irreverent campaign was the work of Sportsbet, the Melbourne-based online betting giant with a history of creating mischief - but not before social media and media outlets worldwide had speculated wildly about who might be responsible. The cheeky stunt generated over six million impressions via social media in just one week, and saw celebrities from Rodney Hogg to Jonathan Agnew and even competitor Ladbrokes call out the campaign on Twitter. The campaign also saw the tongue-in-cheek posters appearing on helicopter banners in a fly-by of England’s training session on Friday, as well as on mobile billboards that were waiting for the England team as they left their hotel on the morning of the match, in which Australia smashed England by 111 runs.