Sure, this guy looks friendly with his teddy bear face but I'm sure he probably has a buddy with a pit bulls head and rocket launchers for arms...

http://news.bbc.co.uk/1/hi/health/6729745.stm

They're programmed to walk up to you, extend a hand, and say (in an Austrian accent), "Come wit me if you vant to live."

" Your clothes. Give them to me. NOW!"