We upgraded a machine to Mountain Lion (10.8.2), but found that parentalcontrolsd was running constantly with high CPU usage. The steps to correct the problem were found on the Apple Support Forums.
- Disable parental controls on all users.
- Delete the folder /Library/Application Support/Apple/ParentalControls
Please note that this command is a little dangerous.
$ sudo rm -rf "/Library/Application Support/Apple/ParentalControls"
- Restart Mac.
- Enable parental controls again.