Someone wants me to help them find out if their partner is cheating on them?

not saying it's me but let's someone asked me to help them find out if their partner thinks they may be .. cheating on them......I would charge of course....I say "I need to get in hold of the person's phone and put in a chip if you want to listen their conversations.....that's not very easy but I can do the facebook or myspace pretty easily...you can also put a device ont heir car to figure out where their going."