I have the same problem uninstalling Plex as has been discussed in a previous thread back in March. I am however, running OS X Lion on my iMac, and when I open /Users/Username to delete the two additional files buried in .../Application Support/Plex/Plex Media Server.app (which I can identify using LittleSnitch), there is no "Library" sub-directory to be found. It appears to be an invisible directory or located elsewhere, at least under Lion. Any suggestions to complete the uninstall would be welcomed. Thanks.