Good idea, you can make it even better (i.e. less accidental filtering) by quoting the phrase and adding a random addition, ex:

    -"tiananmen square 1902481358"

This way it won't interfere if you ever happen to actually want results that mention the place.

Hmm, I'm not sure about my testing now, even with innocuous stuff the AI thing isn't back. Maybe something I did scared it off.