People will go to great lengths to pass certification exams. Sometimes certs are required in order to keep a job, or they will help job seekers find their next gig. The stress levels that people are under to become certified can often times get to extreme levels and sometimes drives them to make poor decisions.
Network World has posted an interesting article on how people cheat on certification exams. In it they discuss how cert seekers will go so far as to hire someone to take an exam for them or use stolen materials to study for an exam.
If caught doing any of these things, it would most likely lead to the revocation of your certification and possibly being banned from taking any further exams from that vendor. The consequences can be as serious as losing your job if you are unable to re-certify. Not an avenue I would recommend anyone travels.