By Stephen Eisenhammer and Silvia Antonioli LONDON (Reuters) – When Nat Rothschild, the co-founder of troubled miner ARMS, insulted his former investment partner on Twitter last week, he showed the power of social media for business leaders seeking publicity – but also the perils of saying the wrong thing. Whilst your dad is an evil genius, the scion of the Rothschild banking dynasty tweeted to Aga Bakrie, the word on the street is that you are extremely DUMB. The tweet made the front pages of media around the world as journalists, used to the measured language of corporate press releases, seized on a seemingly unguarded remark showing that even powerful businessmen can descend to playground taunts. Within 24 hours, his number of followers on Twitter had jumped to 1,700 from 200. But not all business leaders have been so fortunate with their apparently off-the-cuff remarks on social media.