Is the cloud really safe? Well, its mostly safe, especially the more common cloud companies like Drop box and Google Drive. Its more likely that your computer will crash than having the whole company crash and have a melt down. It is possible for the company to crash, but it would be very, very rare and unlikely. Google does give your data to law enforcement, but you are one of millions of users so you shouldn't be too worried. You should also read what the company does in these situations before you use the service. The government and teachers can look at what you put in your cloud, but they most likely won't.
http://www.indystar.com/article/20130331/BUSINESS/303310018/Tech-cloud-companies-safe-
http://www.ektron.com/Blogs/Udaiappa-Ramachandran/The-Pros-and-Cons-of-Cloud-Storage/
http://equitytechnologypartners.com/blog/2012/12/30/pros-and-cons-of-cloud-computing/
