Not many actions are inherently evil or good, in a sense. Motivation is more important when deciding moral alignment of an act.
If someone read your mind for the purpose of learning your bank account numbers, that would be evil. If they read your mind to find out what color you would like your brand new motorbike to be, that's not so evil.
Though, there is the concept of a Right to Mind. A person's privacy is a right, so thoughts, being the most private part of a person, are rights as well. But it's rather vague, considering that mind reading isn't real.