I just found it ridiculous that Doc engineers this huge, complex operation (jumping around time, spying on people, tracing everything back to one incident, using Marty to trick Griff, etc) and it's all just to... keep Marty's kids from getting sent to prison?? Say huh? Yeah I know he says it will eventually destroy the entire McFly family, blah blah blah. But still... that whole storyline just felt really weak and overly contrived to me. Especially following up the great storyline of the first movie.