That sounds more like...I don't know, a three month interview perhaps? Pretty shitty to be on the receiving end of that if you didn't know what was going on. Possibly would be ok if both applicants consented to it in advance. But yeah, it's definitely open to abuse. A bad employer will always find a way to screw you over somehow.
“Today a young man on acid realized that all matter is merely energy condensed to a slow vibration, that we are all one consciousness experiencing itself subjectively, there is no such thing as death, life is only a dream, and we are the imagination of ourselves.” – Bill Hicks