In this day of social networking, it is important to remember that some information should never be discussed or listed publicly. Various profiles provide opportunity to list projects that individuals or companies have been involved with. It is also tempting to tout big accomplishments, especially when it is for a prominent company or organization.
In some industries such as finance and insurance, it is illegal to provide such information. In the security industry, even if a client gives their approval to share information, it should never be posted in a public environment. Even anonymous references should be avoided if there is a possibility of natural association.
Aside from legal, ethical or security reasons, clients who really matter will likely be influenced negatively when they see someone posting such associations. While the initial impression may seem to give credibility for accomplishments, in the end more harm will be done than good.
Always consider, could the information I post be used to harm any party associated.