From the annals of high idiocy, I enjoyed this sequence of emails at BofA:

“Unfortunately it’s screw the shareholders!!” Charles K. Gifford wrote to a fellow director in an e-mail exchange that took place during the call.

“No trail,” Thomas May, that director, reminded him, an apparent reference to the inadvisability of leaving an e-mail thread of their conversation.
…
Shortly after Mr. May’s remark about an e-mail trail, Mr. Gifford said his comments were made in “the context of a horrible economy!!! Will effect everyone.”

“Good comeback,” Mr. May replied.

You have to give Mr. Gifford at least credit for not replying back “OMG Oops!!!” after the first email exchange.