The British Olympic Association has reminded their athletes to act “carefully and responsibly” when using social media after Dai Greene fell foul of the organisation’s guidelines in an online exchange. Greene, the 400 metre hurdles world champion and Britain’s athletics team captain for London 2012, prompted the BOA to reaffirm its stance on social media usage after using language that might be construed as offensive in a conversation with fellow British athlete Martyn Rooney on Twitter in June.