I have had K9 installed on my computer for a while and it has really done a good job, but I found that even after checking off the various categories I could still "dig up" some inappropriate pictures through Google image search, even though the site itself is blocked. (He is really good, the Y"H!! zaken verogil). I tried blocking images through K9, but that blocked all images including icons on GYE.
After a number of attempts, I overcame the problem like this: Besides for blocking categories, K9 also has an option to block specific sites. So I just plugged in "Google images" and it did the trick without interfering with any other sites.
"Blind Beggar" responds:
I use "Image Like Opera" which is a Firefox add-on recommended by GYE. It does a really good job, as do Adblock and Flashblock. The link for "Image Like Opera" for Firefox users is here. On WebChaver it says you can get it for Google Chrome also.