I rewrite the urls on the proxy so Safesearch is enforced. I do this with SquidGuard. The url rewrite rules are as follows.
Force Google image searches to be normal searches.
Code:
rewrite google_imagesearch {
s@http://images.google.com/images?@http://www.google.com/search@ir
s@http://images.google.co.uk/images?@http://www.google.co.uk/search@ir
} Enable SafeSearch
Code:
rewrite google_imagesearch {
s@http://images.google.com/images?@http://images.google.com/images?safe=images&@ir s@http://images.google.co.uk/images?@http://images.google.co.uk/images?safe=images&@ir
} Enable SafeSearch in Strict mode
Code:
rewrite google_imagesearch {
s@http://images.google.com/images?@http://images.google.com/images?safe=on&@ir
s@http://images.google.co.uk/images?@http://images.google.co.uk/images?safe=on&@ir
}
Use one of the above, then alter your default acl.
eg,
Code:
acl {
default {
rewrite google_imagesearch
pass local-ok !local-block !ads !aggressive !drugs !gambling !hacking !porn !proxy !violence !warez all
}
}