Manipulation is done all the time. The media, your boss, school system and the government all have their hand in pointing you in the direction they want you to go rather than where you want to go.
You can't build a reputation on what you are going to do. --Henry Ford
'Evil' depends on what's your interpretation of evil. If a double agent is sent into a terrorist organization and does a little manipulation I can hardly see that as being evil.
It is evil and should never be done unless you are out to save the world but most times people do this for selfish reasons.
We interrupt Is Manipulating Someone An Evil Practice? to share caption from the past:
Today is: 26th May (GMT), in history on the 26th of May, 1964 AD the following event happened:
"Fade Out-Fade In" opens at Mark Hellinger Theater NYC for 199 performances