Necessarily?
If you use magic to rip someone's mind apart, that is a 4th law violation. You have changed their mind. Depending on how you go about ripping their mind apart, it may not be a law breaker. If you blindly tear a mortal's mind apart (with no intention of programming them to a purpose) you might not get a lawbreaker for doing it to a monster (you scrambled without looking in at whatever nastiness is in there). But to a freewilled mortal? Definite Lawbreaker.
I would totally insist on a lawbreaker for someone that read the mind of anything. "When you look into the void, the void looks into you." I don't want to know what is inside a demon's mind. The Lawbreakers represent loss of humanity.
You mean you couldn't just do a Psychomantic Divination? I didn't see anywhere that you have to do a Take Out to read someone's mind.
Of course you didn't see anything about take outs in psychomancy. There is very little actually there. All it says is that emotion reading is like Divination. Se technically Pscyhomancy should only be able to communicate aspects (permanent and temporary) of an emotional or knowledge.
To actually sift through their memories you would have to achieve a take out (203). And as long as the described take out is in line with the situation it works. So if your mental attacks were made with the goal of reading their mind (and you have the power to read minds) then you can take the person out and start plucking memories.