Just to refresh the concept, Dr. Asimov's Three Laws of Robotics aren't real laws. They are a literary plot device. Dr. Asimov knew that there were work arounds for them. He always found reasons to work around the three laws in his robot stories. What you WILL find to be true is this:
1.Robots are machines. Machines, like humans, age and break down if not properly maintained. A faulty machine will injure or kill the first person that is careless.
2. Any military that uses robots on a field of battle will have some type designed for defensive/offensive combat. If you don't want to be killed by a military robot, stay out of it's line of fire.
3. Hobby robots made out of sturdy plastic will bite your fingers just as hard, if not harder, as metal when you grab them in the middle of program execution.
In the recent movie Astroboy, the robots mention in passing about Asimov's three laws. "You know, a robot may not injure a human, yada yada yada." The laws have no effect on these guys. And if you think they should, you need to stay away from your blender. You might like the number of fingers on your hands.