The normal display of African unity in the early stages of a football World Cup was notably absent from social media as many fans from across the continent backed Mexico in the tournament's opening match against South Africa. The memes were light-hearted - including sombreros, mariachi bands and tacos - but they pointed to a dark underbelly. The banter reflected anger over the reports of xenophobic violence in South Africa. A poor South African performance on the pitch led to a 2-0 defeat