This lady crossed a few lines. First of all, this is not tough love. Handcuffing someone against their will is ILLEGAL, it doesn't matter if its your kid.
Lets look at this from a couple angles; first, momma has no idea how to be a parent. Even if what this kid is lacking is a healthy dose of Jesus, the solution isn't to cuff him in a room with nothing but a Bible. That'll just make him hate the Bible, as anyone who has ever taken the time to talk to a teenager will know.
Further more, those who still think this is just tough love, consider this; the kid was still handcuffed when momma left the house. What if there was a fire? Would his death have just been an unfortunate coincidence of being punished at the same time as a fire broke out at the same time that momma wasn't home? No, it would've probably been a manslaughter charge for momma.
The bottom line is that momma is just lazy. She clearly didn't take the time to LISTEN to her kid, and instead figured that Jesus would do the work for her if she kept him chained up long enough (thats how prison works, right?).
EDIT: She should've just sent him to one of those "scared straight" programs like this one:
http://www.onionsportsnetwork.com/articles/kids-in-scaredstraight-program-visit-horrifying-cl,19156/