I don't know what your theory is ("everyone knows exactly why"), but I'll put forth my thesis. 1) Autosuggestions are a sample of the most frequent phrases goo

I don't know what your theory is ("everyone knows exactly why"), but I'll put forth my thesis. 1) Autosuggestions are a sample of the most frequent phrases google users type in 2) This autosuggest list is analyzed statistically and a sentiment score established ranging from 0 (friendly) through 1 (hateful). 3) If the autosuggest list statistics reveal a certain characteristic (e.g. all hateful, or very controversial, etc.), then no suggestions get returned. If I'm wrong that at least in principle this is an automatic, data-driven behavior, then I really feel sorry for the sod who is maintaining a list of what phrases aren't kosher.