If the creator of a software is arrested because its product is used by someone for privacy purposes that are considered illegal, 
then also weapon manufacturers should be arrested because their product is used by someone to kill other people.
And car manufacturers because everyone with a car can easily run over pedestrians.
And chemists because they create chemicals that can kill a lot of people.
And cutlery manufacturers because knives are used all the time in domestic aggressions.
And so on.

A tiny detail: privacy should not be illegal, unlike violence and murder.