Google offers SafeSearch to stop offensive content popping up on your workplace computer or in front of the kids, and Microsoft's rival search engine Bing has a similarly-labelled option. But while Google's system can distinguish between images and text in videos, Bing seems to take a much less subtle approach: if a video sounds remotely raunchy, it gets blocked regardless of actual content.
Blogger Keith du Cros points out that searching for terms such as "gay" and "homosexual" on Bing's default 'moderate' SafeSearch settings produces a note that the content "may return explicit adult content" and hence has been blocked. That might at first seem like a homophobic bias on Microsoft's part, but in fact Bing seems to block anything with vaguely sexual connotations from video search:
It seems like Bing video will often, if not always just completely block results in safesearch if a blacklisted keyword pops up, rather than just filtering out the undesirable content like Google does.
In other words, Bing would block a video of a politician discussing sex education, while Google wouldn't. Both sites would block actual videos of sexual acts (which is the purpose of the filters), but the Bing approach would also block all kinds of largely unrelated content.
It's precisely this kind of unsubtlety that has given filtering in general a bad name, and it certainly suggests that Bing needs to do a lot more work to match Google's search relevance -- image filtering is not exactly a new concept, after all.