Greg, I looked into this slightly. A divorce attorney has informed me that some states may see this as a violation of the Privacy Act as well as a liability on the part of divebuddy.com.
We all want members to do the right thing, but those doing the wrong thing will conduct themselves in that manner regardless of where it is. This would mean that the spouse would need to chase down Myspace.com, Yahoo messenger, AOL messenger, and any other chatroom or IM program log out there. Simply creates a serious legal issue.