Let's assume that it is slippery slope. Where do you draw the line between tools that are 'just tools' and tools that are not 'just tools'?

There are all sorts of them. Most jurisdictions require a license to operate a car, and a slightly harder to get license to operate larger vehicles. There are similar things with planes and explosives and other sorts of chemicals. Guns are restricted in many areas, pistols are restricted in most areas, large knives are restricted in most areas.

Inanimate objects can't be evil.

Guns don't cause crime, cars don't cause accidents, and nuclear weapons don't kill people: their (usually) negligent operators do.

Your argument is basically a straw-man argument/non-argument. No duh that inanimate objects can't be evil. Yet they can be used for evil purposes. And some are more likely to be used for evil purposes than others. How does that really make a difference?

My point is that the focus must be on the operators of such devices, not the devices themselves. For example, the fact that Obama likes to use drones to take out American citizens (and I guess their children and cousins?) suspected of providing material support to terrorists should make us all angry because of the lack of due process, not that a fancy new technology is used.