By Lars Mucklejohn Bosses from the UK’s biggest high street banks have told MPs that social media companies could do more to prevent the increasing amount of fraud originating on their platforms. UK chief executives from Barclays, Lloyds, Natwest and Santander said in a Treasury Committee session that they were working more collaboratively with social media and telecommunications firms to prevent fraud but that there was still progress to be made. “The levels of fraud are increasing, and the impacts on customers are life changing,” Natwest CEO Paul Thwaite told MPs. “Banks can only do so much,…