How long do you think those names will be used, now that they’re out in cyberspace?
These codenames aren't meant to be secret. Their purpose is to differentiate the President and his family from anyone else who Secret Service agents might be referring to over their communication system. So, if Michelle Obama was meeting with someone else named Michelle, there would be no confusion when the agents were talking to one another.
Tough job being a Secret Service agent. A lot of tedium and standing around in crappy weather. It's nowhere near as glamorous as the movies make it out to be.