RBS could really blow up around June when someone figures out exactly what the hell they were doing

Before he was unceremoniously fired as chief executive of Royal Bank of Scotland, Sir Fred Goodwin often said that he had turned the 280-year-old institution into "a sausage machine".
RBS, like other banks, was buying and selling pre-packaged parcels of debt, which started out as mortgages and loans but were put through a corporate mincer and wrapped into packages containing small pieces of hundreds, if not thousands, of loans. Rather like sausages, no one could be entirely sure what was in them – but as long as they paid a decent rate of interest and the bonuses kept flowing, no one cared.

http://www.telegraph.co.uk/finance/4325899/Financial-crisis-just-how-big-is-Britains-toxic-debt.html