Since a few days, I noticed my iMac was running slower. By checking the process manager, I noticed the parentalcontrol process was taking up half a GB of Memory.
A couple of forum posts mentioned the following procedure for fixing this issue:
- desactivate parental controls for all users.
- as root user : delete the directory /Library/Application/support/Apple/parentalcontrols
- reboot.
... and the problem was fixed.