It's used as a surname 99.999% of the time. Looking at
www.namaejiten.com and
www.douseidoumei.net, I've found none with the name 'Hatori' on the 1st site. On the 2nd site though, I've found one with 生鳥 (生 being ha, from 'ha.eru' or 'ha.yasu') but the question would be if that person was named Hatori or not.
Other than that, I've only seen this name mentioned as an idea/suggestion (see
http://5go.biz/fbo/read/2/5704 - in Japanese).
My PNL:
http://www.behindthename.com/pnl/149249