What is “blac” and why are so many people searching for images of it?
Google puts a fair amount of weight on the filename of images when doing matching for image searches. Since filenames don’t usually have spaces, and often don’t have other obvious word delimeters like dashes or underscores, google has to guess where the word boundaries are. The can and surely do use a dictionary with word frequencies as a basis for that guessing. That dictionary is by necessity and definition based on an analysis of a corpus of text. In Google’s case, that corpus seems to be a large part of the world wide web. If you do a word search for blac on the Google web index it will tell you that it has over 2M matching pages (vs about 10M for feline, as a reference point), and it doesn’t even suggest “Black” as an alternate spelling. Therefore, it makes the reasonable assumption that “blac” occurring in the midst of filename or URL is an actual search term and indexes it as such when it comes across a filename like blackhawkdown.jpg.