They're a terrible idea. Explained here - I don't usually do this but I request all my friends and to anyone who sees this post to watch this hour long video. While most of you would want to scroll through your feed just now, I hope you will take the time for it could be an extremely crucial investment for your future. That being said, if you connect to this, I would urge you to share this with as many people as possible. For some, this could be life changing.