Haven’t posted in a while so I thought I’d share a fix I found for Parental Controls and proxy servers.
There appears to be an issue in both Lion and Mountain Lion with Parental Controls and proxy servers, when a user has Parental Controls enabled and they try to access the Internet through a proxy server a blank page is returned, attempting to connect through cURL returns a “empty reply from server” error.
The fix is to execute this command in Terminal
sudo chmod a-x /System/Library/PrivateFrameworks/FamilyControls.framework/Versions/A/Resources/webfilterctl
This removes the execute permission for everyone from the webfilterctl file, which I believe filters SSL connections (If anyone knows what this does for sure please leave a comment).