McAllister, Neil. The 25 greatest blunders in tech history (IMO). New Zealand PCWorld. Feb. 23, 2009.

Listed as a part of the #1 greatest blunder in tech history, e-mail and instant messaging data leaks and security are a considered major problem. A quote:

The web, email, and instant messaging have given criminals unprecedented opportunities for fraud, scams, and electronic spying. In 2007, corporations lost customer data to cyberthieves like never before. And today's vast digital repositories make for very juicy targets that can be copied onto a few DVDs slipped unnoticed in a jacket pocket.

More reason to control those leak apps, notably e-mail and instant messaging, be it OCS, SameTime, Jabber or all of the public and financial IM solutions.