Informed consent implies that you have all pertinent information before you make a decission, otherwise we are talking about a scam.
A few years ago there was no easy access to information about this organization. They just offer you a Bible study, no strings attached, they don't want to change your religion...but once you are in, strong social pressure and the use of various forms of manipulation make breaking free very difficult.
They depend on this type of control to keep people in. If witnesses enjoyed the freedom other religions that they have the cheek to criticize have, they would have no followers at all.
Individuals that scam others are dealt with as crooks, it shouldn't be any different if you are a corporation.