Comment 30 for bug 462994

As speculated above, can confirm mission-control is holding onto user log in data. After sudo apt-get purge'ing empathy and telepathy-*, mission-control is still left running in memory. I ended up doing 'sudo kill -9 pid' on the mission-control process in question before re-installing empathy, but a reboot of the system would probably do well to clear it as well. So quick recap, I did the following:

Went into Keyring manager GUI and removed entries for offending accounts
Opened terminal and did the following:
sudo apt-get purge empathy
sudo apt-get purge telepathy*
ps aux | grep -i mission
sudo kill -9 4462
ps aux | grep -i mission
sudo rm -rf .config/Empathy/ .gconf/apps/empathy/
sudo apt-get install empathy
sudo apt-get install telepathy-haze

Could have probably avoided going into the keyring and removing entries if I had purged empathy and telepathy first, but didn't think to test it. Not having the mission-control process die on a purge seems like a major over site though.