Citigroup is in neck deep. Not only did they lend unsecured loans to both WCOM & Enron, it was their bonds broker and street advisor at Salomon Barney Frank (a Citigroup company) who artificially inflated the value of WCOM until the fraud was revealed.
That's right, they lent them millions in unsecured loans while acting as street advisor on the relative atrength of same said company. Any conflict of interest there? No, nothing more to see here. Move along.