For months and months now, people have been complaining in multiple Google Web Search Help forums that Google won't give them their adult content. They want to use Google Image search to fine pornography but they cannot.
Well, now there is a technical reason why they may not be able to see the pornography.
AJ from Google, after digging around, found one possible cause. In short, Google had one feature that resulted in turning on another feature, when the older feature was discontinued.
The reason why this is happening is because previously, Google offered a feature called NoSSL. This would disable HTTPS for Search, and was intended to allow organizations to enable SafeSearch for all of their users. (HTTPS is what secures connections to and from Google, so that user queries can't be read by a third party.)Last year, Google announced SafeSearch VIP, a new way to allow organizations to enable SafeSearch while retaining the security offered by HTTPS. Recently, the NoSSL feature was removed, and users still accessing Google using that feature were automatically migrated to SafeSearch VIP to keep the reason for the original feature working.
If your ISP or network administrator had NoSSL enabled for your network, this new change will have put you into SafeSearch; in that case, there is not an easy way to disable it. This is by design, as the functionality was built for school administrators, who want to keep their students safe.
Now Dean Jackson from Google is also in the thread helping people figure out if their ISP is indeed blocking adult content by accident or on purpose.
So if you can't get your porn on Google, check out the thread.
Forum discussion at Google Web Search Help.