Skype bug - a fix will be rolled out in the next few days
Following an update in June, the Instant Messaging client software Skype developed a bug which according to various users, private messages were unintentionally sent to contacts at random. Users complained about the erratic behavior of sending and receiving of private instant messages and apart from the embarrassment this issue has caused, many see it as a serious breach of privacy. Skype will be rolling out a fix in the next few days.
Read more here - http://www.engadget.com/2012/07/16/skype-privacy-bug/