Even if one of the most famous photographs ever taken wasn't called "tank man", it'd still be pretty weird for there to zero results. Try misspelling "man" or "tank", you'll get many results. "tanke man" says "including results for 'tank man'".
https://en.wikipedia.org/wiki/Tank_Man
and though the image searches do show a bunch of other things (all including "tank man" in the name at least), they _do_ also include the iconic photo at least once:
http://www.maryscullyreports.com/wp-content/uploads/2017/06/...
which I did not see in the bing results...